port argument to RiakClient is "silently" ignored

Recently the RiakClient constructor changed so that you need to pass http_port instead of just port to connect to a non-standard http port. If you pass port, there's a deprecation notice (which isn't echoed by default. You need to pass -Wall (or similar) to python to even see the warning), but it's not clear that it's ignoring it. I think it should either make it clear that it's ignoring it, reject attempts at using the port argument, or (preferred) automatically translate it to http_port or pb_port depending on the protocol setting so that there's a smooth transition path.