Update versions for 1.2.13 release
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
Set javaagent for tools.
Patch by Sam Tunnecliffe, reviewed by brandonwilliams for CASSANDRA-6404
Merge branch 'cassandra-1.2' into cassandra-2.0
Fix CHANGES.txt
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	CHANGES.txt
Fix row tombstones in larger-than-memory compactions
patch by thobbs; reviewed by jbellis for CASSANDRA-6008
clarify that we only collect row-level tombstone in LCR constructor
fix stats to omit purged row tombstone
enhance assertion failure message
add #5125 to CHANGES
Pig: don't assume all DataBags are DefaultDataBags
Patch by Mike Spertus, reviewed by brandonwilliams for CASSANDRA-6420
Merge branch 'cassandra-1.2' into cassandra-2.0