fixing msgpack script response result array serialization

The initial method of serializing arrays did not call writeArrayStart and writeArrayEnd on the msgpack packer. While this worked fine if the top level object was an array, and you were deserializing with the java msgpack lib expecting the missing bytes, if an object contained in the results also included an array (ie a map value), or if you were doing msgpack deserialization in a different language (ie python) deserialization would break. Here, I've fixed that, updated the unit tests, and added some tests I used to debug the problem.

Please note that this patch will break existing rexpro applications relying on the current MsgPackScriptResponse message serialization behavior. However, the current behavior is incompatible with at least one msgpack implementation, and prevents the use of arrays anywhere except the top level result within java applications.