Document a bsdconfig(8) compatibility nit with pkg(7) 1.2.x.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Fix wording from r260842.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Document pw(8) regression when the '-G' flag is used.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation
Fix description of pw(8) regression.

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation