Cleanup the REAGL stuff

Hopefully for good, this time.

re #1109, re #1119 

The H2O stuff needs some more testing, but is at the very least less broken than today ^^.

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There are a bunch of semi-related changes in, some of them of dubious quality ^^.

A couple of notes:
a12015c & 6b21057 might be terrible ideas.

I might also have broken stuff with the UI elements switched to regional updates. Did manage to unbreak the FM at the last minute, so, hey, there's that :D.