Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Pathnames as .Nm arguments in the NAME section isn't a
good idea, as they appear in the whatis(1) output. So
replace them with the lowercase version of the document
title. While here, do some tiny markup fixes.

Update Bluetooth code.

Reviewed by: M. Warner Losh <imp@bsdimp.com>; John Hay <jhay@freebsd.org>
Approved by: M. Warner Losh <imp@bsdimp.com> (mentor)