SSTable metadata(Stats.db) format change

patch by yukim; reviewed by thobbs for CASSANDRA-6356
Fix assertion failure in filterColdSSTables
patch by Tyler Hobbs; reviewed by jbellis for CASSANDRA-6483
merge from 2.0
fix race referencing tokenMetadataCache
patch by jbellis; reviewed by rbranson for CASSANDRA-6485
merge from 1.2
Merge branch 'cassandra-2.0' into trunk
r/m Test.iml
Merge branch 'cassandra-2.0' into trunk
remove dead code
Improve batchlog write performance with vnodes

patch by Jonathan Ellis and Rick Branson; reviewed by Aleksey Yeschenko
for CASSANDRA-6488
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
Merge branch 'cassandra-2.0' into trunk
Slightly improved message when parsing properties for DDL queries

patch by boneill42; reviewed by slebresne for CASSANDRA-6453
caching all calls of cloneOnlyTokenMap is not correct since many callers mutate the result
patch by Aleksey Yeschenko; reviewed by jbellis for CASSANDRA-6488
merge from 1.2
Merge branch 'cassandra-2.0' into trunk
Simplify TokenMetadata.cachedOnlyTokenMap()
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk
Push composites support in the storage engine

patch by slebresne; reviewed by benedict for CASSANDRA-5417