scheme48 with X11 support

Hi,

I've added X11 window support to scheme48 with an (initx11) method which
draws a generic window. There is a rough event processing system which
keeps the window from blocking X11 events and the xputpixel method is under
development but should be easy to fix for X11 folks. Do read the  README
and HACKING.* files in the following scheme48-fb-x11 distributions for
building , http://soft.vub.ac.be/~jceuppen/scheme/

Note that this package generates a 'scheme48-fb' vm binary and needs to be
plugged into scsh this way (scsh must be built on top of it, but this is
not necessary if you only use s48.)

You can do 3D or anything graphical on X11 (e.g. port this to nanoX on the
PSP) with scheme this way. A widget is just a bunch of pixels put on the
window with the xputpixel or putpixel methods and so a button widget
clicked is just shifted in color to produce the press effect :-)

Love,
Johan