Improve batchlog replay behavior and hint ttl handling

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-5314
Merge branch 'cassandra-1.2' into trunk

Conflicts:
	src/java/org/apache/cassandra/db/BatchlogManager.java
	src/java/org/apache/cassandra/db/RowMutation.java
	src/java/org/apache/cassandra/service/StorageProxy.java
	test/unit/org/apache/cassandra/db/HintedHandOffTest.java
cqlsh: drop CQL2/CQL3-beta support

patch by Aleksey Yeschenko; reviewed by Brandon Williams for
CASSANDRA-5585