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
Set SO_LINGER to 0 for netty
Merge branch 'cassandra-2.1' into trunk
improve concurrency of repair process

patch by yukim; reviewed by krummas for CASSANDRA-6455
Fix counters in supercolumns during live upgrades from 1.2

patch by Aleksey Yeschenko; reviewed by Sylvain Lebresne for
CASSANDRA-7188
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/db/CounterUpdateColumn.java
Merge branch 'cassandra-2.1' into trunk
Fix merging schemas with re-dropped keyspaces

patch by Aleksey Yeschenko; reviewed by Pavel Yaskevich for
CASSANDRA-7256
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/db/DefsTables.java
Merge branch 'cassandra-2.1' into trunk

Conflicts:
	src/java/org/apache/cassandra/db/DefsTables.java
Reduce totalBlockFor() for LOCAL_* consistency levels

patch by Nicolas Douillet; reviewed by Aleksey Yeschenko for
CASSANDRA-8058
Merge branch 'cassandra-2.0' into cassandra-2.1

Conflicts:
	CHANGES.txt
	src/java/org/apache/cassandra/service/DatacenterWriteResponseHandler.java
Merge branch 'cassandra-2.1' into trunk
Keep sstable level when bootstrapping

Patch by marcuse; reviewed by iamaleksey for CASSANDRA-7460