Merge -r 1430928:1430929 from trunk to branch-2. Fixes: MAPREDUCE-1700. User supplied dependencies may conflict with MapReduce system JARs.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1430936 13f79535-47bb-0310-9956-ffa450edef68