Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

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

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

[urtwn] migrate urtwn out into sys/dev/urtwn/ .

There's some upcoming work to add new chipset support here and I'd
like to only add 802.11n support to one driver, instead of both
urtwn and rtwn.

There's also missing support for things like 802.11n, some powersave
work, bluetooth integration/coexistence, etc, and also newer parts
(like 8192EU, maybe some 11ac parts, not sure yet.)

So, this is hopefully the first step in a longer set of steps to unify
rtwn/urtwn and extend it with more interesting chipset and functionality
support.

Reviewed by: kevlo

Adding urtwn(4) firmware and related changes.

Reviewed by: rpaulo
Approved by: sbruno (mentor)