Avoid NPE when creating table w/ frozen sets, lists

Patch by Robert Stupp; reviewed by Tyler Hobbs for CASSANDRA-8104
Add the ability to cleanup files after CqlBulkRecordWriter succeeds

Patch by Paul Pak, reviewed by Piotr Kołaczkowski for CASSANDRA-7777
Merge branch 'cassandra-2.0' into cassandra-2.1
Gossip should ignore generation numbers too far in the future

patch by jasobrown; reviewed by driftx for CASSANDRA-8113
ninja-remove unneeded continue statement
Properly handle exceptions during native proto decode

Patch by Tyler Hobbs; reviewed by Aleksey Yeschenko for CASSANDRA-8118