cqlsh should automatically disable tracing when selecting from system_traces

patch by Philip Thompson and Mikhail Stepura; reviewed by Mikhail Stepura for CASSANDRA-7641
Merge branch 'cassandra-2.0' into cassandra-2.1.0
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	bin/cqlsh
Merge branch 'cassandra-2.1' into trunk
Merge branch 'cassandra-2.0' into cassandra-2.1.0
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Validate IPv6 wildcard addresses properly

patch by Robert Stupp; reviewed by Aleksey Yeschenko for CASSANDRA-7680
Merge branch 'cassandra-2.1' into trunk
Merge remote-tracking branch 'origin/trunk' into 7740-broken-udf-parsing