Consolidated the Registry into a single variable.

Review: https://reviews.apache.org/r/18158
Added new documentation page for frameworks.

 * Consolidate framework list on a new page
 * Add short description to each framework
 * Remove frameworks from home and powered-by, link to new page instead

Review: https://reviews.apache.org/r/18328
Logged ZooKeeper session expiration event in group.
Added hostname attribute to framework and displayed it in master's web
ui.

Review: https://reviews.apache.org/r/18361
Fixed ROOT_CGROUPS_Write test.

Review: https://reviews.apache.org/r/18532
Added new documentation page for tools and linked it from the homepage.

Review: https://reviews.apache.org/r/18547
Modified the Registrar to notify callers only _after_ the storage operation completes.

Review: https://reviews.apache.org/r/18341
Assign bool directly to JSON::Value.

This change removes the workaround that was necessary now that
https://issues.apache.org/jira/browse/MESOS-939 is committed.

Review: https://reviews.apache.org/r/18540
Patched glog to compile demangle.cc with clang.

Review: https://reviews.apache.org/r/18307
Fixed compile errors in lib stout when using Clang 3.5 on Ubuntu
13.10.

Review: https://reviews.apache.org/r/18425
Fixed compile errors in mesos with Clang 3.5 on Ubuntu 13.10.

Review: https://reviews.apache.org/r/18426
Fixed fetcher to ignore unrecognized file names.

Review: https://reviews.apache.org/r/18565
Added notice to autotools to dump GCC version.

Review: https://reviews.apache.org/r/18599
Enforced log coordinator demotion after a write is discarded.

Review: https://reviews.apache.org/r/18488
Fixed incorrect stderr to stdout pipe routing in configuration phase.

Review: https://reviews.apache.org/r/18608
Added a test for CFS cpu limits in the cpu isolator.

Review: https://reviews.apache.org/r/18276
Changed SIGKILL to SIGTERM in command executor shutdown.

If command executor processes doesn't respond to SIGTERM during
shutdown, the slave will call containerizer->destroy() after
EXECUTOR_SHUTDOWN_GRACE_PERIOD seconds. MesosContainerizer::destroy()
calls SIGKILL on the process tree which effectively is the necessary
signal escalation.

Review: https://reviews.apache.org/r/18604
Renamed Cfs test to properly disable in non-root non-linux environment.

Review: https://reviews.apache.org/r/18634
Fixed Cpu isolator to use integral values for cfs quota.

Review: https://reviews.apache.org/r/18639
Refactored cpu control writes.

Review: https://reviews.apache.org/r/18642