Changes between ppsclock 1.2 beta and 1.3 beta

    - sys/sun4m: Added support for the sun4m (requires SunOS 4.1.3).

    - sys/genassym: Added "mini" genassym to support sites without full
    SunOS source.

    - (general): Add support for non-source (e.g. OBJect only sites).

    - *.ps: Split schematics apart; now there is magnavox.ps for the
    Magnavox Magnavox 538534-3 converter and b-and-b.ps for the B&B
    Electronics 422CEC.

    - README: Fix typo in kernel configuration step (2). (Thanks to
    Brian Tierney, tierney@george.lbl.gov.) Document need for revision
    1.3 or higher roms with the SS1.

    - sys/sundev/ppsclock.c: Added support for PPS signal. This is
    compiled only if the PPS_SYNC option is defined in the kernel and
    requires modified kernel support for the PPS clock discipline.
    Flames may be sent to Dave Mills (mills@udel.edu).
