Dont try to set repairedAt on old sstables

Patch by marcuse; reviewed by jbellis for CASSANDRA-7913
Merge branch 'cassandra-2.1' into trunk
update changes/news for 7917
Add human readable option to nodetool outputs.

Patch by Michael Nelson, reviewed by brandonwilliams for CASSANDRA-5433
Merge branch 'cassandra-2.1' into trunk
Consistently name get/set trace probability JMX calls.

Patch by Nitzan Volman, reviewed by brandonwilliams for CASSANDRA-6926
Don't try to shutdown client servers if they don't exist.

Patch by Steve Nelson, reviewed by brandonwilliams for CASSANDRA-7889
Merge branch 'cassandra-2.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Don't output nonsense ownership without a keyspace

Patch by Steven Nelson, reviewed by brandonwilliams for CASSANDRA-7173
Merge branch 'cassandra-2.1' into trunk
GCInspector more closely tracks GC; cassandra-stress and nodetool report it

patch by benedict; reviewed by tjake
Merge branch 'cassandra-2.1' into trunk
cassandra-stress supports whitelist mode for node config

patch by benedict; reviewed by tjake for CASSANDRA-7658
Merge branch 'cassandra-2.1' into trunk
ninja fix rethrow InterruptedException in cassandra-stress Timing.snap
Merge branch 'cassandra-2.1' into trunk
remove orphanable field 'connectionFactory'
fix format string to match the number of input values
Merge branch 'cassandra-2.1' into trunk