revert #7275
Merge branch 'cassandra-1.2' into cassandra-2.0
merge from 2.0
Allow counter mutations in UNLOGGED batches

patch by tjake; reviewed by Aleksey Yeschenko for CASSANDRA-7351
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	test/unit/org/apache/cassandra/cql3/DeleteTest.java