Add support for 24-bit RGB linear modes (3 bytes per pixel). Add code to
configure the S3 card in 24bpp mode. Add code to render and convert
24bpp to 32bpp because DOSBox's render/scalar code can't handle 24bpp
natively. Changed VESA modelist so that VESA 1.2 modes 0x100-0x11F
follow the v1.2 spec and run as 24bpp and moved original DOSBox 32bpp
modes from that range up to 0x200. Doing this allows COMA's "Parhaat"
1997 demo to run correctly by offering a true 24bpp mode for it to
choose instead of allow it to first choose a 32bpp mode and then render
24bpp to it, which doesn't look visually appealing.