Prepare release 1.0.0-rc6.
Merge pull request #163 from mediacrossinginc/mx_multiseed

Allow multiple comma-separated hosts in spark.cassandra.connection.host
Conflicts:
	CHANGES.txt
Merge branch 'b1.0' of https://github.com/datastax/spark-cassandra-connector
Fix CHANGES.txt: Multiple hosts in spark.cassandra.connection.host moved from 1.1 to 1.0