Handle short slice start/finishes of different lengths

Patch by Tyler Hobbs; reviewed by Sylvain Lebresne as a follow-up for
CASSANDRA-6825
Revert "Don't shut ExpiringMap down."

This reverts commit d4ec31f21eb83502bd523c057bce2d3b249b3d80.

Conflicts:
	CHANGES.txt
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/db/marshal/CompositeType.java
	test/unit/org/apache/cassandra/db/marshal/CompositeTypeTest.java
Merge branch 'cassandra-2.0' into cassandra-2.1
Handle short slice start/finishes of different lengths

Patch by Tyler Hobbs; reviewed by Sylvain Lebresne as a follow-up for
CASSANDRA-6825
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/db/marshal/CompositeType.java
	test/unit/org/apache/cassandra/db/marshal/CompositeTypeTest.java
Skip range calculations for range slices on LocalStrategy keyspaces

Patch by Tyler Hobbs; reviewed by Jonathan Ellis for CASSANDRA-6906
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/service/StorageProxy.java