Add .classpath, .project, .settings and target to svn:ignore.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1437844 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch 'apache/trunk' into MAPREDUCE-4838
Do null check for the getters of the newly added attributes.