Added support for mice with rotational axes.   The wheel on wheelie mice can now be used to tweak effect parameters.  Mice with multiple wheels are supported.

    Should you be fortunate enough to own a Digital Research 2-wheeled mouse, model number of DRMOUSE4DS , I just acquired one and have written a patch which you can apply to the SVGALib 1.4.2 source. Set your mouse type in libvga.config to DRMOUSE4DS and you can take advantage of the two wheels!