Fixed and added docs about clusters.json, other misc markdown adjustments.

Bugs closed: AURORA-55

Reviewed at https://reviews.apache.org/r/17072/
Add a DISCLAIMER.

Bugs closed: AURORA-57

Reviewed at https://reviews.apache.org/r/17086/
Commit e1aee67 re-creates src/main/python/twitter after namespace change
occurring.

Bugs closed: AURORA-60

Reviewed at https://reviews.apache.org/r/17106/
Adding license header to missing files (py, bash, thrift, ...)

Bugs closed: AURORA-3

Reviewed at https://reviews.apache.org/r/17110/
Only export counters in TaskVars after SchedulerActive event.

Bugs closed: AURORA-59

Reviewed at https://reviews.apache.org/r/17095/
Only make the SchedulerDriver available after registered() has been called.

I've also removed some functions from the Driver interface, since they should
be used exclusively by SchedulerLifecycle.

Bugs closed: AURORA-45

Reviewed at https://reviews.apache.org/r/16995/
Improve test coverage for TaskAssignerImpl.

Bugs closed: AURORA-63

Reviewed at https://reviews.apache.org/r/17133/
Improve test coverage for CronJobManager.

Bugs closed: AURORA-62

Reviewed at https://reviews.apache.org/r/17131/
AURORA-75: Update all dependencies coming from twitter commons and upgrade to guava 15.

Bugs closed: AURORA-75

Reviewed at https://reviews.apache.org/r/17161/
Show an error message in the UI when scheduler returns an invalid response.

Show an error message when a call to the thrift end point returns an invalid response.

Testing Done:
gradle clean build.

Tested with local scheduler. Scheduler shows an error message (ex: when storage is not ready)

Bugs closed: AURORA-18

Reviewed at https://reviews.apache.org/r/17014/
Added docs about apache email setup.

Reviewed at https://reviews.apache.org/r/17068/
Moved readonly thrift API calls into ReadOnlyScheduler.

Moved readonly thrift calls into ReadOnlyScheduler.

Not updating the release version, since the change should have no impact on the consumers of AuroraSchedulerManager service.

Testing Done:
gradle clean build
gradle run to test with local UI.

Reviewed at https://reviews.apache.org/r/17205/
AURORA-58: Cache hashCode in generated immutable classes.

I've also silenced the code generator output by default, cleaning up the output
when building via gradle.

Bugs closed: AURORA-58

Reviewed at https://reviews.apache.org/r/17088/
AURORA-116: Use only a single write transaction to save HostAttributes in resourceOffers.

Bugs closed: AURORA-116

Reviewed at https://reviews.apache.org/r/17351/
Fix maintenance command documentation and host/filename logic.

Reviewed at https://reviews.apache.org/r/16983/
Add a stat that tracks the number of threads waiting for the storage lock.

Reviewed at https://reviews.apache.org/r/17353/
Avoid using protobuf equals().

Reviewed at https://reviews.apache.org/r/17359/
Avoid using protobuf equals() on OfferID.
Merged all of the open clientv2 reviews into one unified change.

- Add clientv2 implementation of "job status" with jobkey wildcard support.
- Add clientv2 implementations of "job update" and "job list"
- Add clientv2 implementation of "job restart"
- Add clientv2 implementation of "job cancel_update"
- Extract more common options into "options.py".
- General code cleanup.

This supersedes the following reviews:
- https://reviews.apache.org/r/17153/
- https://reviews.apache.org/r/17051/
- https://reviews.apache.org/r/17154/
- https://reviews.apache.org/r/16306/

Testing Done:
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 3 items

src/test/python/apache/aurora/admin/test_mesos_maintenance.py ...

=========================== 3 passed in 0.29 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 2 items

src/test/python/apache/aurora/client/test_binding_helper.py ..

=========================== 2 passed in 0.30 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 6 items

src/test/python/apache/aurora/client/test_config.py ......

=========================== 6 passed in 0.40 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 6 items

src/test/python/apache/aurora/client/api/test_disambiguator.py ......

=========================== 6 passed in 0.25 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/client/api/test_job_monitor.py .

=========================== 1 passed in 0.22 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 6 items

src/test/python/apache/aurora/client/api/test_restarter.py ......

=========================== 6 passed in 0.21 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 47 items / 1 skipped

src/test/python/apache/aurora/client/api/test_scheduler_client.py ...............................................

===================== 47 passed, 1 skipped in 0.59 seconds =====================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 20 items

src/test/python/apache/aurora/client/api/test_instance_watcher.py ........
src/test/python/apache/aurora/client/api/test_health_check.py ............

========================== 20 passed in 0.24 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 26 items

src/test/python/apache/aurora/client/api/test_updater.py ..........................

========================== 26 passed in 0.43 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 6 items

src/test/python/apache/aurora/client/api/test_quota_check.py ......

=========================== 6 passed in 0.09 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 25 items

src/test/python/apache/aurora/client/cli/test_cancel_update.py ..
src/test/python/apache/aurora/client/cli/test_create.py ....
src/test/python/apache/aurora/client/cli/test_diff.py ...
src/test/python/apache/aurora/client/cli/test_kill.py .....
src/test/python/apache/aurora/client/cli/test_restart.py ...
src/test/python/apache/aurora/client/cli/test_status.py .....
src/test/python/apache/aurora/client/cli/test_update.py ...

========================== 25 passed in 1.42 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 24 items

src/test/python/apache/aurora/client/commands/test_cancel_update.py ..
src/test/python/apache/aurora/client/commands/test_create.py ......
src/test/python/apache/aurora/client/commands/test_diff.py ...
src/test/python/apache/aurora/client/commands/test_kill.py ...
src/test/python/apache/aurora/client/commands/test_listjobs.py ..
src/test/python/apache/aurora/client/commands/test_restart.py ...
src/test/python/apache/aurora/client/commands/test_status.py ..
src/test/python/apache/aurora/client/commands/test_update.py ...

========================== 24 passed in 1.12 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/client/commands/test_run.py .

=========================== 1 passed in 0.30 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/client/commands/test_ssh.py .

=========================== 1 passed in 0.28 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 12 items

src/test/python/apache/aurora/client/hooks/test_hooked_api.py ............

========================== 12 passed in 0.23 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 4 items

src/test/python/apache/aurora/client/hooks/test_non_hooked_api.py ....

=========================== 4 passed in 0.22 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/common/test_aurora_job_key.py .

=========================== 1 passed in 0.05 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/common/test_cluster.py .

=========================== 1 passed in 0.02 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 4 items

src/test/python/apache/aurora/common/test_clusters.py ....

=========================== 4 passed in 0.11 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 2 items

src/test/python/apache/aurora/common/test_cluster_option.py ..

=========================== 2 passed in 0.04 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 3 items

src/test/python/apache/aurora/common/test_http_signaler.py ...

=========================== 3 passed in 0.15 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 7 items

src/test/python/apache/aurora/config/test_base.py .......

=========================== 7 passed in 1.24 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/config/test_constraint_parsing.py .

=========================== 1 passed in 0.10 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 6 items

src/test/python/apache/aurora/config/test_loader.py ......

=========================== 6 passed in 0.13 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 10 items

src/test/python/apache/aurora/config/test_thrift.py ..........

========================== 10 passed in 1.40 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 4 items

src/test/python/apache/aurora/executor/test_executor_detector.py ....

=========================== 4 passed in 0.05 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 4 items

src/test/python/apache/aurora/executor/test_executor_vars.py ....

=========================== 4 passed in 0.12 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 5 items

src/test/python/apache/aurora/executor/test_thermos_task_runner.py .....

========================== 5 passed in 17.95 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 2 items

src/test/python/apache/aurora/executor/common/test_directory_sandbox.py ..

=========================== 2 passed in 0.07 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 3 items

src/test/python/apache/aurora/executor/common/test_health_checker.py ...

=========================== 3 passed in 1.41 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/executor/common/test_status_checker.py .

=========================== 1 passed in 0.05 seconds ===========================
============================= test session starts ==============================
platform darwin -- Python 2.7.2 -- pytest-2.5.1
collected 1 items

src/test/python/apache/aurora/executor/common/test_task_info.py .

=========================== 1 passed in 0.14 seconds ===========================
Build operating on targets: OrderedSet([PythonTestSuite(src/test/python/apache/aurora/BUILD:all)])
src.test.python.apache.aurora.admin.mesos_maintenance                           .....   SUCCESS
src.test.python.apache.aurora.client.api.disambiguator                          .....   SUCCESS
src.test.python.apache.aurora.client.api.instance_watcher                       .....   SUCCESS
src.test.python.apache.aurora.client.api.job_monitor                            .....   SUCCESS
src.test.python.apache.aurora.client.api.quota_check                            .....   SUCCESS
src.test.python.apache.aurora.client.api.restarter                              .....   SUCCESS
src.test.python.apache.aurora.client.api.scheduler_client                       .....   SUCCESS
src.test.python.apache.aurora.client.api.updater                                .....   SUCCESS
src.test.python.apache.aurora.client.binding_helper                             .....   SUCCESS
src.test.python.apache.aurora.client.cli.job                                    .....   SUCCESS
src.test.python.apache.aurora.client.commands.core                              .....   SUCCESS
src.test.python.apache.aurora.client.commands.run                               .....   SUCCESS
src.test.python.apache.aurora.client.commands.ssh                               .....   SUCCESS
src.test.python.apache.aurora.client.config                                     .....   SUCCESS
src.test.python.apache.aurora.client.hooks.hooked_api                           .....   SUCCESS
src.test.python.apache.aurora.client.hooks.non_hooked_api                       .....   SUCCESS
src.test.python.apache.aurora.common.test_aurora_job_key                        .....   SUCCESS
src.test.python.apache.aurora.common.test_cluster                               .....   SUCCESS
src.test.python.apache.aurora.common.test_cluster_option                        .....   SUCCESS
src.test.python.apache.aurora.common.test_clusters                              .....   SUCCESS
src.test.python.apache.aurora.common.test_http_signaler                         .....   SUCCESS
src.test.python.apache.aurora.config.test_base                                  .....   SUCCESS
src.test.python.apache.aurora.config.test_constraint_parsing                    .....   SUCCESS
src.test.python.apache.aurora.config.test_loader                                .....   SUCCESS
src.test.python.apache.aurora.config.test_thrift                                .....   SUCCESS
src.test.python.apache.aurora.executor.common.directory_sandbox                 .....   SUCCESS
src.test.python.apache.aurora.executor.common.health_checker                    .....   SUCCESS
src.test.python.apache.aurora.executor.common.status_checker                    .....   SUCCESS
src.test.python.apache.aurora.executor.common.task_info                         .....   SUCCESS
src.test.python.apache.aurora.executor.executor_detector                        .....   SUCCESS
src.test.python.apache.aurora.executor.executor_vars                            .....   SUCCESS
src.test.python.apache.aurora.executor.thermos_task_runner                      .....   SUCCESS

Bugs closed: aurora-53, aurora-54

Reviewed at https://reviews.apache.org/r/17185/
AURORA-122: Add an abstraction for secondary indices, introduce an index on slave host.

Bugs closed: AURORA-122

Reviewed at https://reviews.apache.org/r/17372/