Resource Monitoring 7: Archived terminated executor statistics.

From: Ben Mahler <benjamin.mahler@gmail.com>
Review: https://reviews.apache.org/r/9095

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1449840 13f79535-47bb-0310-9956-ffa450edef68
Resource Monitoring 8: Added cgroups::stat primitive
and implemented cgroup resource collection.

From: Ben Mahler <benjamin.mahler@gmail.com>
Review: https://reviews.apache.org/r/9145

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1449841 13f79535-47bb-0310-9956-ffa450edef68