add deprecation warning to cli
Follow-up for 6327

patch by krummas; reviewed by slebresne for CASSANDRA-6327
Fix AssertionError when doing set element deletion

patch by slebresne; reviewed by iamaleksey for CASSANDRA-6341
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk