Exposed a master statistic for outstanding resource offers.

From: Ben Mahler <benjamin.mahler@gmail.com>
Review: https://reviews.apache.org/r/9127

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452568 13f79535-47bb-0310-9956-ffa450edef68
Properly cleaned up cgroups.

Review: https://reviews.apache.org/r/9408

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452569 13f79535-47bb-0310-9956-ffa450edef68
Fixed allocator, gc and master tests.

Review: https://reviews.apache.org/r/9690

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452570 13f79535-47bb-0310-9956-ffa450edef68
Changed noisy allocator logging from LOG(INFO) to VLOG(1).

From: Ben Mahler <benjamin.mahler@gmail.com>
Review: https://reviews.apache.org/r/9711

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452571 13f79535-47bb-0310-9956-ffa450edef68
Fixed file.cpp logging.

From: Ben Mahler <benjamin.mahler@gmail.com>
Review: https://reviews.apache.org/r/9712

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452573 13f79535-47bb-0310-9956-ffa450edef68
Fixed ExecutorInfo comparision and example tests.

Review: https://reviews.apache.org/r/9723

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1452574 13f79535-47bb-0310-9956-ffa450edef68