I am not really satisfied yet with how the UI redrawing in the app now
works (during startup, which of course is more or less all the app
does so far).

It can take quite some time before a "link" (function to be called)
posted with PostUserEvent() gets run (if there are lots of
time-consuming other "user events" in the queue already, or
something?), and blocking the UI thread for that time is not
acceptable. Will have to come up with some more complicated solution.

Change-Id: Icab20183df3bc4980ae33f0502d10397802cc391