Rename ANTI JOIN to LEFT ANTI JOIN for consistency with LEFT SEMI JOIN.

Change-Id: I8171b2d44b45529fdbd040d5709aaeb9f13facfa
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3873
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: jenkins