This fixes on gtk version being able to invite to an SMS game using
relayID. I don't know why not transmitting port is ok; maybe android
doesn't use the port or gets it some other way, e.g. it's hard-coded for
each variant.
It's useful when testing to have the remote device play without human
interaction. So add an option, and UI to trigger it, for the players
created remotely in response to an invitation to be robots. There are
guards in place to catch the feature slipping into a release build.
