Even more betterer time zone picker

If at all possible, use friendly names. I'm near Seattle, but I'm still America/Los_Angeles, and that doesn't make sense to a lot of people.
Figure out which time zones are identical going forward and collapse them. (Hm. Who wins?)
I would like to optgroup this thing by local time, but wtforms doesn't support optgroups.
Probably don't need to show both UTC offset and local time. I'm way more likely to know what time it than what my offset is.
A map would be so nice, sigh!

eevee / floof