HADOOP-9154. SortedMapWritable#putAll() doesn't add key/value classes to the map. Contributed by Karthik Kambatla.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1446183 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9281-trunk-gd