optimize AtomicBTree
patch by Benedict Elliott Smith; reviewed by jbellis for CASSANDRA-6692
Merge branch 'cassandra-2.1' into trunk
Allow per-dc enabling of hints
patch by Sankalp Kohli; reviewed by Lyuben Todorov for CASSANDRA-6157
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Allow repairing between specific replicas
patch by Sankalp Kohli; reviewed by Lyuben Todorov for CASSANDRA-6440
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Improve repair tasks(snapshot, differencing) concurrency

patch by yukim; reviewed by sankalp kohli for CASSANDRA-6566
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/repair/RepairJob.java
	src/java/org/apache/cassandra/repair/RepairSession.java
Merge branch 'cassandra-2.1' into trunk
Fix replaying pre-2.0 commit logs

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-6714
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/db/commitlog/CommitLogDescriptor.java
	src/java/org/apache/cassandra/db/commitlog/CommitLogReplayer.java
Merge branch 'cassandra-2.1' into trunk
no need for toLowerCase() and equalsIgnoreCase() at the same time
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Support negative timestamps in DateType.fromString

patch by slebresne; reviewed by iamaleksey for CASSANDRA-6718
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk