Survey jabber:iq:gateway support

Cheogram.com has a cute little screenshot that makes it seem like using this bridge is easy as pie.

And I would like it to be easy as pie! It should be easy as pie! But that screenshot is fibbing at least a little bit, because it's on Gajim which is the only client I currently know of with reliable and full support + UI for the jabber:iq:gateway address translation protocol. So there's an assumption I think is faulty in here that I would like to solve with a bet: I bet that most XMPP clients (even weighting "most" by their userbase) do not implement jabber:iq:gateway.

This issue is for logging the results of our research.