Tall pixels can now be used in resolution minimum 320x400, and Tall pixels minimum 640x200. (instead of 640x400 for both)
Fixed: There was incorrect error recovery when trying to use a fullscreen mode too small to use wide/tall/double pixel.
Little code cleanup in the different pixel renderers.
git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@631 416bcca6-2ee7-4201-b75f-2eb2f807beb1