WINTERMUTE: Remove useless memcpy
WINTERMUTE: Factor out simple additive/subtractive copy functions
WINTERMUTE: Factor out simple additive/subtractive copy functions
WINTERMUTE: Factor out colormod blitting
WINTERMUTE: Factor out switches
WINTERMUTE: Factor out regular colormod code
WINTERMUTE: Factor out additive colormod
WINTERMUTE: Factor out subtractive
WINTERMUTE: Factor out fast binary blending
WINTERMUTE: Factor out with function pointers
WINTERMUTE: Factor out with function pointers
WINTERMUTE: Factor out with function pointers