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
Make the CL native protocol code match the on in 2.0

patch by slebresne; reviewed by jasobrown for CASSANDRA-6347
SSTable/SSTableReader cleanup

patch by yukim; reviewed by jbellis for CASSANDRA-6355