add thrift-server and LMAX Disruptor licences
Correctly validate sparse composite cells
patch by Tyler Hobbs; reviewed by jbellis for CASSANDRA-5855
Merge remote-tracking branch 'origin/cassandra-2.0.0' into cassandra-2.0.0
make scrubbing collection-aware
merge from 1.2
Merge branch 'cassandra-2.0.0' into cassandra-2.0