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

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

Add Bluetooth compatibility shims. Inspired by Linux BlueZ and NetBSD.

Discussed with: Iain Hibbert plunky -at- rya-online -dot- net of NetBSD
MFC after: 1 month