Updated the release guide for removing old releases from svn.
Do not require the SlaveID in reconciliation requests.

Review: https://reviews.apache.org/r/23542
Fixed a bug in the test environment for disabling certain cgroups tests.

Review: https://reviews.apache.org/r/23781
Minor fix for libev-unbundled in python setup.

Review: https://reviews.apache.org/r/23785
Removed unnecessary includes and inline definitions.

Dominic's Hamon review request: https://reviews.apache.org/r/18295
mergeable to today's master version, this is a lightened version to
make review easier.  Note I see an improvements of ~7.5% of the
compile time.

Review: https://reviews.apache.org/r/23745
More docs for attributes and resources.

Review: https://reviews.apache.org/r/23752
Removed trailing '/' in Makefile.am.

Review: https://reviews.apache.org/r/23829
Introduce script for generating test coverage report.

Review: https://reviews.apache.org/r/23828
Add back declaration of stream operator.

Review: https://reviews.apache.org/r/23873
Allowed LoadGeneratorFramework to read password from a file.

Review: https://reviews.apache.org/r/23695
Made LoadGeneratorFramework a check program instead of a bin program.

Review: https://reviews.apache.org/r/23696
Fixed a memory leak in limiter.hpp.

Review: https://reviews.apache.org/r/23916
Add missing whitespace to coverage script

Review: https://reviews.apache.org/r/23934
Fixed a bug in port mapping test cleanup function.

Review: https://reviews.apache.org/r/23955
Fixed a bug that caused 'make dist' unable to patch leveldb.

Review: https://reviews.apache.org/r/24061
Fixed the master to accept a file:// based zk flag.

Review: https://reviews.apache.org/r/23997
Converted bool returns to Try<Nothing> in stout/os.hpp.

Review: https://reviews.apache.org/r/20493
Mesos converted to use Try<Nothing> returns from stout/os.hpp.

Review: https://reviews.apache.org/r/20494
Cleaned up TODO comments for ZK file:// URL support.
Task health status change notifications

The reusable health check program added in #22579 emits TaskStatus
messages when the task under supervision first becomes viable (when the
task passes its first health check).  It also emits a message when a
task changes state from healthy to unhealthy.

However, the scheduler should be notified for _every_ observed change in
health status.  It's easy to imagine cases where the scheduler wants to
wait a while before killing an unhealthy task, but still be notified of
status changes so that load balancers may be updated, etc.  This patch
therefore causes the scheduler to also be notified when an unhealthy
task becomes healthy again.

Review: https://reviews.apache.org/r/23966