Remove socksipy dependency from http_signaler.

Remove socksipy dependency from http_signaler.
Fixes small issue in environment bootstrapping script.
Increments twitter.aurora artifact version numbers.
Add troubleshooting section to vagrant.md

Add a troubleshooting section to the vagrant documentation.
Remove test for require_contact_email
Fix the twitter.thermos sdist to properly depend upon twitter.thermos.monitoring.
Remove the deprecated instance ID field.
Bumping up twitter-aurora version to 0.0.11
Fixing the scope for hasProperty in publish
Adding random jitter on pending task rescheduling after startup
Upgrade Thrift to 0.9.1

This upgrades the Java side of Aurora to libthrift 0.9.1 and the thrift compiler 0.9.1.
This change covers the following:
1. Upgrades the compiler and runtime.
2. Fixes the Aurora source code to use the new way of accessing Thrift
   Constants.
3. com.twitter.common.ThriftServer was copied into the source tree and modified
   to deal with the breakage caused by
   https://issues.apache.org/jira/browse/THRIFT-745
Fixing error message for a held lock.
Returning custom response code in case of lock conflict
Document ASF review process and tooling.
Retrieve credentials from file.
Bumping up twitter-aurora version to 0.0.12
Update rbt to unstable version and update docs.

This change updates rbt for automatically-generated commit message
(./rbt patch --commit) support. It also updates the contributor
documentation to suggest its use for all commits to master.

Testing Done:
This review was posted using the new workflow.

Verified that ./rbt works in a clean repo and one with an old version of
rbtools bootstrapped.

Reviewed at https://reviews.apache.org/r/16073/
Use bash instead of sh for bootstrap scripts.

Testing Done:
vagrant up

Bugs closed: AURORA-5

Reviewed at https://reviews.apache.org/r/16094/
Adding support for a 'locked job warning' in client APIs
Add top level LICENSE file.

Reviewed at https://reviews.apache.org/r/16090/
Enable integration with hooks on a failed update.

Adding support for err hooks when update is rolled back or failed. Hooks use thrift ResponseCode to detect operation failure, so updater has to simulate an ERROR response code to properly support error hooks.

Also, failed_instances no longer tell the truth as far as update status goes. Converted to use failure count check to determine update success.

Testing Done:
./pants src/test/python/twitter/aurora/client/api:all

Reviewed at https://reviews.apache.org/r/16139/
Merge branch 'skarumuri/MESOS-4712_bower' of https://github.com/mansu/incubator-aurora into skarumuri/MESOS-4712_bower