Update stress to use driver 2.0.4
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Include stress yaml examples in release and deb

patch by tjake and mshuler; reviewed by mshuler and slebresne for CASSANDRA-7717
Merge branch 'cassandra-2.1.0' into cassandra-2.1
Merge branch 'cassandra-2.1' into trunk
Support pure user-defined functions

Patch by Robert Stupp; reviewed by Tyler Hobbs for CASSANDRA-7395