Prevent NPE on FD conviction race

Patch by brandonwilliams, reviewed by thobbs for CASSANDRA-7940
Add CASSANDRA-7450 to CHANGES
Merge branch 'cassandra-2.0' into cassandra-2.1
Follow up to CASSANDRA-7719

patch by Aleksey Yeschenko; reviewed by Jake Luciani for CASSANDRA-7719
Fix RowIndexEntry to report correct serializedSize
patch by Pavel Yaskevich; reviewed by Aleksey Yeschenko for CASSANDRA-7948
Merge branch cassandra-2.0 into cassandra-2.1
Include schema_triggers CF in readable system resources

patch by Adam Holmberg; reviewed by Aleksey Yeschenko for CASSANDRA-7967
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/service/ClientState.java
Provide visibility into prepared statements churn

patch by Nate McCall; reviewed by Aleksey Yeschenko for CASSANDRA-7921
Allow permissions cache to be set via JMX

Patch by brandonwilliams, reviewed by aleksey for CASSANDRA-7968
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
rm dead code
Allow propagating multiple gossip states atomically

Patch by brandonwilliams, reviewed by jasobrown for CASSANDRA-6125
Log unclean client disconnect excs at DEBUG

Patch by Graham Sanderson; reviewed by Tyler Hobbs for CASSANDRA-7849
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/transport/Message.java
	src/java/org/apache/cassandra/transport/messages/ErrorMessage.java
(cqlsh) Add command line option for cqlshrc file path.

patch by Aaron Ploetz; reviewed by Mikhail Stepura for CASSANDRA-7131
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
Warn when evicting prepared statements from cache

patch by Robbie Strickland; reviewed by Aleksey Yeschenko for
CASSANDRA-7930
Add method to invalidate permission cache via JMX

Patch by brandonwilliams, reviewed by aleksey for CASSANDRA-7977
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt