Merging changes from HADOOP-639, HADOOP-791 and HADOOP-827 into 0.9 branch, preparing for 0.9.2 release.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/branches/branch-0.9@487697 13f79535-47bb-0310-9956-ffa450edef68
16 files changed