kickstart/bootmenu

    Building on base code provided by olsen which was extracted
    from the monitor handling, I reworked the bootmenu to support
    DblPAL and DblNTSC (both VGAOnly) correctly and to provide
    these modes also for a boot without Startup-Sequence. This
    means that once the initial reboot of SetPatch has installed
    the ROM update, there is typically no need anymore for a 15kHz
    capable display or a flicker fixer. For compatibility reasons,
    the initial mode will still be 15kHz. So when you press the
    mouse buttons, you will get into the boot menu with a 15kHz
    display mode. To let you know that you are in the boot menu,
    the boot menu will now blink the LED while you still hold
    both mouse buttons. You then select the VGA style bootmenu by
    pressing CTRL-LALT-DEL-BACKSPACE. This key combination has been
    chosen, so that noone can complain that a 15kHz only display
    got destroyed "by accident". I have thought about allocating a
    battmem bit to force Dbl modes on bootup, but this is probably
    not too great an idea. If someone wants to boot into a readable
    display without S-S, he might as well use the majik keys, once
    he has triggered the boot menu.
    Froze 44.2.
    *blush* I overlooked two things. Old C= code freed the
    VisualInfo before freeing the gadgets. As the bootmenu
    previously used less than system friendly methods to switch
    between PAL and NTSC the bug in the code did notturn into an
    issue until now. Also, due to a fairly stupid oversight, either
    the PAL or the NTSC monitor did not get set up leading to a
    paranoia dead end Alert that I put in. The bootmenu is now
    truly system friendly and does not poke the chips anymore.
    Froze 44.3.
    The bootmenu can now be invoked with the keyboard if the HELP
    key is pressed right after(!) the reboot. The key can not be
    held during reboot. Also, keyboard based mouse pointer movement
    in the bootmenu is now possible as key presses are ignored now
    while any SHIFT/ALT/AMIGA qualifiers are held down.
    Froze 44.4.

