CASSANDRA-5800 follow-up

patch by Aleksey Yeschenko; reviewed by Tyler Hobbs for CASSANDRA-5800
Merge branch 'cassandra-1.2' into cassandra-2.0.0

Conflicts:
	src/java/org/apache/cassandra/db/SystemKeyspace.java
Merge branch 'cassandra-2.0.0' into cassandra-2.0