Fix error when doing reverse queries with static columns

patch by graham sanderson; reviewed by slebresne for CASSANDRA-7490
Merge branch 'cassandra-2.0' into cassandra-2.1.0

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
fix missing test build dep for pig-test
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
ninja fix LegacySSTable test with new versioned files from 2.0
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Fix LegacySSTableTest KS name
Use unsafe mutations where possible in unit tests

Patch by Lyuben Todorov; reviewed by Tyler Hobbs for CASSANDRA-6969
Fix race condition during pending range calculation

Patch by Josh McKenzie; reviewed by Tyler Hobbs for CASSANDRA-7390