I checked in some stuff that should make svgalib Linux binaries work 
reasonably well. There are some bad, bad hacks in it, some of which
I thought of (or had been suggested to me) some time ago, but I
felt so guilty about doing this that it took me about 3 months, a trauma
and professional help to check this in ;)

A few things that people need to know when running Linux svgalib binaries:

1). The binaries need root permissions to be able to mess with the I/O ports
    (just as they need that under Linux)
2). You need a [/emul/linux]/usr/local/lib/libvga.config file to configure
    the svga library. Look either in the svgalib distribution or on the
    nearest Linux system you can find how it should look like.
3). Make the following links in /emul/linux/dev:
    ttyS? -> /dev/tty0?
    console -> /dev/tty (WARNING: this trick will work for svgalib binaries,
                         but may have strange results for others)
    mouse -> {whatever serial port your mouse is on)
4). VT switching won't work with binaries that use the keyboard stuff in
    the Linux svgalib. There are 2 reasons for this, the first one being
    that the svgalib code doesn't take care of any keyboard state saving/
    restoring in the case of a VT switch, the second is that in the mode
    that the svgalib KB code works in, VT switching is apparently not possible
    under Linux anyway.
5). You may get strange results if you run, for example, XFree in one VT, 
    and a Linux svgalib binary in another, when, say XFree is using
    some chipset-specific extended mode, and svgalib is using some default
    VGA mode. There isn't much the emulation can do about that.


Yes, the svgalib version of Doom for Linux (linuxsdoom) works with this,
for those of you who are _still_ playing that (geez ;-)).

Let me know if there are any problems

- Frank