Unified screenshot code and moved it to video.c, it is now independent of both renderer and platform;
The EGA/(S)VGA overscan now also works for CGA, PCjr, Tandy, and CGA-using Amstrads;
Fixed EGA/(S)VGA overscan operation so it works correctly with scrolling and panning;
Fixed 320x200x32K and 320x200x64K modes on the ET4000/W32p;
Fixed the Video 7 1024i chip ID and video memory options, fixes#431;
Fixed a banking bug in the S3 cards, fixes Windows 9x and NeoPaint.