MAPREDUCE-4837. Add webservices for Jobtracker. Contributed by Arun C Murthy

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1440233 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4423. Checkpoint exception may cause fatal damage to fsimage.  Contributed by Chris Nauroth


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1440259 13f79535-47bb-0310-9956-ffa450edef68