Renamed slaves/frameworks activated/deactivated

The existing terminology is confusing both for "slaves.deactivated" and
"frameworks.activated". Currently a deactivated slave actually
represents a removed/shutdown slave and "frameworks.activated" map holds
both activated and deactivated frameworks.
In order to make things look clear, rename the following:
* master.slaves.deactivated -> master.slaves.removed
* master.slaves.activated -> master.slaves.registered
* master.frameworks.activated -> master.frameworks.registered
* allocator.slaveDisconnect -> allocator.slaveDeactivate
* allocator.slaveReconnected -> allocator.slaveReactivated

Review: https://reviews.apache.org/r/23147
Re-enabled health check tests

Currently the health check tests are disabled as it was flaky. Part of the reason is that all assertions was EXPECTs instead of ASSERTs so it will continue to execute.
Another issue was it's currently discovering the path to launch health check executable from the command executor main argv[0] path.
However, the correct path is to launch the generated script that does library path resolution, which is the parent of .libs.

Review: https://reviews.apache.org/r/23443
Fixed a deadlock bug in Mutex.

Review: https://reviews.apache.org/r/23592
Disabled flaky low level scheduler tests.
Fixed a bug in port mapping metrics.

Review: https://reviews.apache.org/r/23544
Allowed the port mapping isolator to tolerate early child process
termination.

Review: https://reviews.apache.org/r/23659
Disabled HealthCheckTest.ConsecutiveFailures flaky test.
Added support for installing stout headers.

Review: https://reviews.apache.org/r/23563
Added support for installing libprocess headers.

Review: https://reviews.apache.org/r/23535
Unified status update logging in the master.

Review: https://reviews.apache.org/r/23661
Fixed a clang compilation issue in master.cpp.
Fixed the checkpoint configuration bug in example frameworks.

Review: https://reviews.apache.org/r/23561
Generate u32 filter handle in user level to work around MESOS-1617.

Review: https://reviews.apache.org/r/23701
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