tried to make the calendar faster by prerendering to a texture. It didn't work and I don't really want to learn the intricacies of openGL trying to make it so.
Revert "Well... now the timeline is still correct if you've scrolled... other than that I don't really remember"

This reverts commit 73501185c0e8f95b3fe124976e76bcabdb11e614.

Conflicts:
	gui.py
ok *really* reverting now
Performance...improved, perhaps?