Fix requests with skipMetadata=false returning no metadata

patch by slebresne; reviewed by thobbs for CASSANDRA-8054
Set SO_LINGER to 0 for netty
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
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
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
Fix spin loop in AtomicSortedColumns

patch by graham sanderson and benedict; reviewed by yukim for
CASSANDRA-7546
Committing revised 7927 for review
cleaning up import ordering on JVMStabilityInspector
removing extra + from JVMStabilityInspector javadocs from rebase
Adding support for die policy to commit log
make inspector less greedy.  Factor inspector logic into killer
CHANGES.txt, simplify StabilityInspector
a little further tidying, merged KillerForTests into parent JVMStabilityInspector