Merged the 3.03 patch changes

Changed Files:
    redalert/hires/title.pcx
    redalert/nchires/bmap.vqp
    redalert/local/conquer.eng
    redalert/local/credits.eng
$(EXT) instead of hard-coded ".exe" in makefile, $(MIXER_DIR) macro added
reworded readme, fixed link to patches repo
Added missing interior tiles
Added fan-made desert and winter theaters
Moved original theater pallets to be with tiles
Also added generated vortex variants