convert to using pidfile...  This prevents multiple wpa_supplicants
running at the same time causing problems w/ wifi not working..

the patch will be submitted upstream...  The next step if someone wants
to push it upstream is to break os_unix.c up so that all these other
utilities don't need libutil..

Reviewed by:	rpaulo
Permit changing cpu mask for cpu set 1 in presence of drivers
binding their threads to particular CPU.

Changing ithread cpu mask is now performed by special cpuset_setithread().
It creates additional cpuset root group on first bind invocation.

No objection:	jhb
Tested by:	hiren
MFC after:	2 weeks
Sponsored by:	Yandex LLC
Remove the incomplete Tegra 2 code, nobody was maintaining it. The AC100
never booted to single user mode.

It can be brought back if someone is willing to get it into a stable state
and maintain it.
With the migration from GNATS to Bugzilla, we no longer need a tool to
graph GNATS PR statistics.  It would be nice to have a similar tool for
the new bug database, but that would likely be a from-scratch rewrite.