Make it possible to run lptcontrol on a printer port which does not

Make it possible to run lptcontrol on a printer port which does not
actually have a printer connected or online:
- MAKEDEV:		remove all signs of lpa
			add lpctl? devices (minor # = unit + 128)
- usr.sbin/Makefile	add lptcontrol
- sys/i386/isa/lpt.c	implement the LP_BYPASS flag: when a unit is
			opened with this flag set, the printer is
			not primed, and no check is made to see that
			the printer is online.  This can only be used
			to pass ioctls.  (giving us /dev/lpctl?)
- lptcontrol.c		use /dev/lpctl? (LP_BYPASS)
			-f flag removed, -u flag added
- lptcontrol.8		document changes in lptcontrol
			rewrite using mandoc macros
Submitted by:	Geoff.