Log USING TTL/TIMESTAMP in a counter update warning

patch by Aleksey Yeschenko; reviewed by Sylvain Lebresne for
CASSANDRA-6649
Sleep for RING_DELAY before replacing with same IP
Patch by brandonwilliams reviewed by Tyler Hobbs for CASSANDRA-6622
Don't exchange schema between nodes with different versions

patch by Aleksey Yeschenko; reviewed by Piotr Kołaczkowski for
CASSANDRA-6695
Use real node messaging versions for schema exchange decisions

patch by Aleksey Yeschenko; reviewed by Piotr Kołaczkowski for
CASSANDRA-6700
IN on the last clustering columns + ORDER BY DESC yield no results

patch by slebresne; reviewed by thobbs for CASSANDRA-6701
Fix SecondaryIndexManager#deleteFromIndexes()

patch by Sergio Bossa; reviewed by Sam Tunnicliffe for CASSANDRA-6711
Fix snapshot repair not snapshotting coordinator

patch by yukim; reviewed by sankalp kohli for CASSANDRA-6713
Support negative timestamps in DateType.fromString

patch by slebresne; reviewed by iamaleksey for CASSANDRA-6718
Don't attempt cross-dc forwarding interface/mixed-version cluster with 1.1
patch by Jeremiah Jordan; reviewed by jbellis for CASSANDRA-6732
Avoid NPEs when receiving table changes for an unknown keyspace

patch by Aleksey Yeschenko; reviewed by Sylvain Lebresne for CASSANDRA-5631
Catch memtable flush exceptions during shutdown
patch by Sergio Bossa; reviewed by jbellis for CASSANDRA-6735
Completer shall always return a collection
Document that TTL <= 0 means no TTL
update changes
r/m populate_io_cache_on_flush from yaml (per-table since #4694)
Add CMSClassUnloadingEnabled JVM option
Patch by Jonathan Lacefield, reviewed by brandonwilliams for
CASSANDRA-6541
Fix resetAndTruncate:ing CompressionMetadata

Patch by kvaster, reviewed by marcuse for CASSANDRA-6791
fix typo in cfmbean comparator
nodetool no longer shows node joining
patch by driftx; reviewed by Vijay for CASSANDRA-6811
Fix CQL doc