MAPREDUCE-5451. MR uses LD_LIBRARY_PATH which doesn't mean anything in Windows. Contributed by Yingda Chen.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1539413 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-YAHOO-258-trunk-gd