Update versions for 1.2.13 release
dht模块注释
Randomize batchlog candidates selection

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-6481
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	NEWS.txt
	build.xml
	debian/changelog
Merge branch 'cassandra-2.0' into trunk
Set javaagent for tools.
Patch by Sam Tunnecliffe, reviewed by brandonwilliams for CASSANDRA-6404
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk
Fix CHANGES.txt
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
Merge branch 'cassandra-2.0' into trunk
Fix row tombstones in larger-than-memory compactions
patch by thobbs; reviewed by jbellis for CASSANDRA-6008
Merge branch 'cassandra-2.0' into trunk
clarify that we only collect row-level tombstone in LCR constructor
merge from 2.0
fix stats to omit purged row tombstone
Merge branch 'cassandra-2.0' into trunk
add back shouldPurge check before counter merging
Merge remote-tracking branch 'origin/trunk' into trunk
enhance assertion failure message