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

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

Bluetooth SIG is being difficult and keep moving specification
documents away from being public accessible. Replace link to
the Bluetooth specification document with the document name.

Pointed out by: SoftLover < slserg at uic dot tula dot ru >
MFC after: 3 days

Insert zero-width break points to fix warnigns in nroff output,
and reduce whitespace stretching in groff PS output.

groff-foo by: ru

Revise markup.

Add bluetooth.device.conf(5) man page

MFC after: 3 days