groff: add recent FreeBSD releases

(reduces `manlint' noise)
mdocml: sync std strings with groff
world: remove spurious Pp macros
libc: proper FreeBSD version and some Mt macros for mails
a couple more Mt macros for author emails
kernel/drm: Fix the LINT build.
drm/radeon: Import the Radeon KMS driver from FreeBSD

* Credits for porting an updated version of this driver from Linux
  mainly go to Jean-Sébastien Pédron <jean-sebastien.pedron@dumbbell.fr>

* Compatibility layer for running 32-bit applications on 64-bit systems
  left out

Additional credits from the FreeBSD import message:

This driver is based on Linux 3.8 and a previous effort by kan@.

More informations about this project can be found on the FreeBSD wiki:
    https://wiki.freebsd.org/AMD_GPU

Help from:	kib@, kan@
Tested by:	avg@, kwm@, ray@,
		Alexander Yerenkow <yerenkow@gmail.com>,
		Anders Bolt-Evensen <andersbo87@me.com>,
		Denis Djubajlo <stdedjub@googlemail.com>,
		J.R. Oldroyd <fbsd@opal.com>,
		Mikaël Urankar <mikael.urankar@gmail.com>,
		Pierre-Emmanuel Pédron <pepcitron@gmail.com>,
		Sam Fourman Jr. <sfourman@gmail.com>,
		Wade <wade-is-great@live.com>,
		(probably other I forgot...)
HW donations:	kyzh, Yakaz