Add sanity check of $JAVA on startup
patch by Robert Stupp; reviewed by Michael Shuler for CASSANDRA-7676
merge from 2.0
Merge branch 'cassandra-2.1' into trunk
Notify DT subscribers when a column family is truncated

patch by Sam Tunnicliffe; reviewed by Aleksey Yeschenko for
CASSANDRA-8088
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
Merge branch 'cassandra-2.1' into trunk
Shutdown JVM on OOM

patch by Josh McKenzie; reviewed by Aleksey Yeschenko for CASSANDRA-7507
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	src/java/org/apache/cassandra/db/compaction/CompactionManager.java
Allow concurrent use of CQLBulkOutputFormat
patch by Paul Pak; reviewed by Piotr Kolaczkowski for CASSANDRA-7776
Merge branch 'cassandra-2.1' into trunk
Integrate Sigar library and add basic OS performance checks on startup

Patch by Amit Kumar and Josh McKenzie; reviewed by tjake for (CASSANDRA-7838)
Fix requests with skipMetadata=false returning no metadata

patch by slebresne; reviewed by thobbs for CASSANDRA-8054
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	src/java/org/apache/cassandra/cql3/ResultSet.java
	src/java/org/apache/cassandra/cql3/statements/SelectStatement.java
Merge remote-tracking branch 'origin/trunk' into 7813-udf-keyspace