YARN-521. Augment AM - RM client module to be able to request containers only at specific locations (Sandy Ryza via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1503526 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-YAHOO-226-trunk-gd