Reduce likelihood of contention on local paxos state locking

Patch by Aleksey Yeschenko; reviewed by Benedict Elliott Smith for CASSANDRA-7359
Merge branch 'cassandra-2.1' into trunk
CASSANDRA-7359 CHANGES.txt
Merge branch 'cassandra-2.1' into trunk
suggest cassandra-tools package
Merge branch 'cassandra-2.1' into trunk
Fix race in Thrift server that can exhaust the pool of worker threads
patch by Christian Rolf and jbellis for CASSANDRA-6788
Merge branch 'cassandra-1.2' into cassandra-2.0
Ninja-fix counter-in-primary-key validation exception message
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	src/java/org/apache/cassandra/cql3/statements/CreateTableStatement.java
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk