Fix execution of LOCAL_QUORUM queries with SimpleStrategy

patch by alexliu68; reviewed by slebresne for CASSANDRA-6545
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	src/java/org/apache/cassandra/db/ConsistencyLevel.java
Wait for gossip to settle before accepting client connections
patch by Chris Burroughs; reviewed by Tyler Hobbs and jbellis for CASSANDRA-4288
merge from 2.0