YARN-331. Fill in missing fair scheduler documentation. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1434991 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-4923. Add toString method to TaggedInputSplit. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1434994 13f79535-47bb-0310-9956-ffa450edef68
YARN-302. Fair scheduler assignmultiple should default to false. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1434997 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'branch-2' of github.com:griddynamics/yhadoop-common into branch-2-gd
Merge branch 'branch-2-gd' of github.com:griddynamics/yhadoop-common into fb-HADOOP-9170-branch-2-gd