Pull up following revision(s) (requested by mrg in ticket #820):

usr.bin/midiplay/midiplay.1: revision 1.20
usr.bin/midiplay/midiplay.1: revision 1.21
usr.bin/midiplay/midiplay.c: revision 1.31
usr.bin/midiplay/midiplay.c: revision 1.32

if just parsing don't try to read the uninitialised device name,
or display the unit number.

add a "-s" option that sends an ALL_SOUNDS_OFF midi event.  very
useful after an interrupted midiplay leaves notes on.

Merge options without arguments in synopsis.

Sync usage with manpage.

(martin)