YARN-1284. LCE: Race condition leaves dangling cgroups entries for killed containers. (Alejandro Abdelnur via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1530494 13f79535-47bb-0310-9956-ffa450edef68
Add missing file TestCgroupsLCEResourcesHandler for YARN-1284.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1530495 13f79535-47bb-0310-9956-ffa450edef68
YARN-976. Document the meaning of a virtual core. (Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1530501 13f79535-47bb-0310-9956-ffa450edef68
Fix position of YARN-461 in CHANGES.txt

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1530506 13f79535-47bb-0310-9956-ffa450edef68