Faster Cassandra::Composite#hash
Faster Cassandra::Composite#hash

Old one was silly

On my box this speeds a multiget from ~9k col/s to ~12k cols/s

stipple/cassandra_new,cassandra-rb/cassandra,stipple/cassandra_new,cassandra-rb/cassandra,stipple/cassandra_new,cassandra-rb/cassandra,cassandra-rb/cassandra,stipple/cassandra_new