Added support for QOS1 for messages received from the server. Add qos argument to subscribe. Auto ack after callback is run
Added check for valid QOS (0 or 1)
Merge pull request #29 from ennui2342/qos1

Added support for QOS1 for messages received from the server
Merge remote-tracking branch 'upstream/master' into stream
Payload for Stream now doesnt include the topic headers and msgid