Track metrics at a keyspace level

Patch by brandonwilliams, reviewed by yukim for CASSANDRA-6539
fix wrong patch commit
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into cassandra-2.1
Fix memtable copy bug causing rangetombstones to be missed

patch by tjake; reviewed by benedict got CASSANDRA-7371
Upgrade netty to 4.0.20
Don't insert tombstones that hide indexed values into 2i

patch by Sam Tunnicliffe; reviewed by Aleksey Yeschenko for
CASSANDRA-7268
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/db/index/SecondaryIndexManager.java
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	src/java/org/apache/cassandra/db/index/SecondaryIndexManager.java
Handle empty CFs in Memtable#maybeUpdateLiveRatio()

patch by Christian Spriegel; reviewed by Aleksey Yeschenko for
CASSANDRA-7401
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/db/Memtable.java
Increase socket bind backlog to 500
Patch by Oleg Anastasyev, reviewed by brandonwilliams for CASSANDRA-7236
Merge branch 'cassandra-2.0' into cassandra-2.1
fix heap size on Windows 32bit VM
patch by Joshua McKenzie; tested by Philip Thompson for CASSANDRA-7353
add file:/// on Windows to -Dcassandra.config value
patch by Marco Tulio Avila Cerón; reviewed by Lyuben Todorov for CASSANDRA-7398
Clean up gossiper fully after shadow round.

Patch by brandonwilliams, reviewed by thobbs for CASSANDRA-7318
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
Clean up gossiper fully after shadow round.

Patch by brandonwilliams, reviewed by thobbs for CASSANDRA-7318
nodetool doesn't error when ~/.cassandra is inaccessible

Patch by Kirk True, reviewed by brandonwilliams for CASSANDRA-6449
Merge branch 'cassandra-2.0' into cassandra-2.1