FastDoom VESA HighRes test build

New high resolution modes available for VESA 2.0 video cards (both direct rendering and backbuffered rendering). Also new optimizations.

• 320x240 -> FDM240D.EXE / FDM240R.EXE
• 512x384 -> FDM384D.EXE / FDM384R.EXE
• 640x400 -> FDM400D.EXE / FDM400R.EXE
• 640x480 -> FDM480D.EXE / FDM480R.EXE
• 800x600 -> FDM600D.EXE / FDM600R.EXE
• 1024x768 -> FDM768D.EXE / FDM768R.EXE
• 1280x1024 -> FDM1024D.EXE / FDM1024R.EXE