CBQE-2198: upr_bin_client for testrunner

* Add upr opcodes to memcachedConstants
* Add upr operations into a separate client (upr_bin_client)

Until we are able to move to public python sdk and gain upr support adding this to our internal client. This is necessary because pyupr cannot do advanced failure cases like ssh and stop nodes or stream during view/xdcr.
Considered porting pyupr itself but it duplicates mc_bin so made this to inherit instead

Example stream request of 100 items from vbucket0.
        client = UprClient()
        client.open_producer('mystream')

        vbucket = 0
        response = client.stream_request(vbucket, 0, 100, 0, 0, 0)
        stream = client.get_stream(vbucket)

        while stream.has_message():
            message = stream.next_message()

Change-Id: I783a6d8e323196472cc71d8eb17d232f06544a00
Reviewed-on: http://review.couchbase.org/35721
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>