Fix completion problems breaking clqshlib tests

The recent changes in the python driver APIs have caused some completion problems as indicated by 2 of these failing tests:

http://cassci.datastax.com/job/trunk_cqlshlib/579/testReport/

The third failing test, test_timestamp_output, has been failing for some time due to uncertainty on what to do regarding timezone conversion but it too can be changed to reflect the fact that we convert the timestamp to UTC.

Finally, max_window_size_seconds was recently added to the compaction properties and this caused 2 more tests to fail. It cannot be seen on Jenkins because of the relative import problem introduced by CASSANDRA-9304.