Rewrite, and always call, ABSC#localCopy
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	src/java/org/apache/cassandra/db/ArrayBackedSortedColumns.java
	src/java/org/apache/cassandra/db/Memtable.java
Fix potential NPE
Merge branch 'cassandra-2.1' of https://git-wip-us.apache.org/repos/asf/cassandra into cassandra-2.1
Fix BB relative get
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk