Log Message:
Update Apache Cassandra to 1.2.16.

 * Add UNLOGGED, COUNTER options to BATCH documentation (CASSANDRA-6816)
 * add extra SSL cipher suites (CASSANDRA-6613)
 * fix nodetool getsstables for blob PK (CASSANDRA-6803)
 * Add CMSClassUnloadingEnabled JVM option (CASSANDRA-6541)
 * Catch memtable flush exceptions during shutdown (CASSANDRA-6735)
 * Don't attempt cross-dc forwarding in mixed-version cluster with 1.1
   (CASSANDRA-6732)
 * Fix broken streams when replacing with same IP (CASSANDRA-6622)
 * Fix upgradesstables NPE for non-CF-based indexes (CASSANDRA-6645)
 * Fix partition and range deletes not triggering flush (CASSANDRA-6655)
 * Fix mean cells and mean row size per sstable calculations
   (CASSANDRA-6667)
 * Compact hints after partial replay to clean out tombstones
   (CASSANDRA-6666)
 * Log USING TTL/TIMESTAMP in a counter update warning (CASSANDRA-6649)
 * Don't exchange schema between nodes with different versions
   (CASSANDRA-6695)
 * Use real node messaging versions for schema exchange decisions
   (CASSANDRA-6700)
 * IN on the last clustering columns + ORDER BY DESC yield no results
   (CASSANDRA-6701)
 * Fix SecondaryIndexManager#deleteFromIndexes() (CASSANDRA-6711)
 * Fix snapshot repair not snapshotting coordinator itself (CASSANDRA-6713)
 * Support negative timestamps for CQL3 dates in query string
   (CASSANDRA-6718)
 * Avoid NPEs when receiving table changes for an unknown keyspace
   (CASSANDRA-5631)
 * Fix bootstrapping when there is no schema (CASSANDRA-6685)
 * Fix truncating compression metadata (CASSANDRA-6791)
 * Fix SSTable not released if stream session fails before starts
   (CASSANDRA-6818)