ispppcontrol(8) actually controls sppp logic, sys/net/if_spppsubr.c.
	this seems to be generic to sppp, and not very specific to isdn4bsd.  
	could we move it upwards to usr.sbin/spppcontrol, or could we just
	rename the binary?  i would like to add a couple of functionalities,
	namely ways to switch from cisco HDLC to normal PPP, and vice versa.

	(or should we add that to ifconfig, as media options?  not sure)

itojun