XPmaxFonts()
  Report how many fonts can be loaded at once
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  Function:    XPmaxFonts()

               This function returns how many fonts can be
               loaded into the EGA/VGA at once. It will become
               clear later why this can be handy at some
               times. When MaxFonts returns 0, it means that
               there's no EGA/VGA installed, otherwise it
               returns a number between 1 and 4 (dependant on
               how many memory is located on the EGA/VGA card)
               which indicates how many fonts can be loaded at
               some time. Loading 1 font may generally be
               enough, but extra fonts may prove useful when
               one wishes to display a set of 512 characters,
               and switch quickly for instance between
               underline, Italic and normal font.

  Syntax:      XPmaxFonts()

  Arguments:   None.

  Returns:     A numeric value, between 0 and 4.

  Usage:       * - Suppose one needs at least 2 Fonts..
               if XPmaxFonts() < 3
                    Msg('Go buy some EGA/VGA Memory!')
                    quit
               endif