Added 'timed_tests.sh' script to help investigate the cause of hanging tests.

Review: https://reviews.apache.org/r/23700
Added libprocess and stout to doxyfile.

Previously, we only scanned src/ and include/. This patch adds
3rdparty/libprocess/src, 3rdparty/libprocess/include and
3rdparty/libprocess/3rdparty/stout.

Review: https://reviews.apache.org/r/24481
Modified the default for ephemeral ports per container.

Review: https://reviews.apache.org/r/24461
Temporarily disabled HealthcheckTest.ConsecutiveFailures test due to
MESOS-1613.
Fixed allocator to do allocations per slave rather than per framework.

Review: https://reviews.apache.org/r/24356
Retry freeze in cgroups TasksKiller to workaround MESOS-1689.

Review: https://reviews.apache.org/r/24511
Added overloads to 'process::defer()' to dispatch lambda function
to a specific pid.
Added authorization support for "/shutdown" endpoint and updated
ACLs format.
Add ContainerInfo and Volumes proto defs

Review: https://reviews.apache.org/r/24349
Redirect docker logs

Review: https://reviews.apache.org/r/24464
Add new Docker configurations