Fix handling of concurrent directory creation failure

patch by Ryan Fowler; reviewed by Aleksey Yeschenko for
CASSANDRA-6459
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk
Fix test build
Merge branch 'cassandra-1.2' into cassandra-2.0
Merge branch 'cassandra-2.0' into trunk
remove dead fields
fix ClassCastException for #6462
Merge branch 'cassandra-2.0' into trunk
CHANGES
Merge branch 'cassandra-2.0' into trunk
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
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