Completer shall always return a collection
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into cassandra-2.1
fix CME in SessionInfo updateProgress affecting netstats
patch by Josh McKenzie; reviewed by Tyler Hobbs for CASSANDRA-6577
Merge branch 'cassandra-2.0' into cassandra-2.1
Fix overflow of memtable_total_space_in_mb
patch by Benedict Elliott Smith; reviewed by jbellis for CASSANDRA-6753
Authentication works
Merge branch 'cassandra-2.1' into CASSANDRA-6307-cqlsh-driver

Conflicts:
	pylib/cqlshlib/cql3handling.py