HADOOP-9832. [RPC v9] Add RPC header to client ping (daryn)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1510805 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5399. Unnecessary Configuration instantiation in IFileInputStream slows down merge. (Stanislav Barton via Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1510813 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9817. FileSystem#globStatus and FileContext#globStatus need to work with symlinks. (Colin Patrick McCabe via Andrew Wang)



git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1510816 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd