HADOOP-9908. Fix NPE when versioninfo properties file is missing. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1520333 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5159. Secondary NameNode fails to checkpoint if error occurs downloading edits on first checkpoint. Contributed by Aaron T. Myers.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1520363 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HDFS-4312-trunk-gd