Info tab: interface picker

[chucker]

In the long run, I really want the source list instead:

Too bad there are multiple UI glitches (e.g. #4, #8) that we can't easily fix on our end.

So for 1.0, let's do a picker instead. It's what NU did, too.

[chucker]

• [x] reduce width
• [x] either select first entry or make it clearer
• [x] hide other interfaces
• [x] un-break statistics