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
Re-enable HealthCheckTest.ConsecutiveFailures test