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

Add initial Atheros AR91XX support.

This works well enough to bring a system up to single-user mode
using an MDROOT.

Known Issues:

* The EHCI USB doesn't currently work and will panic the kernel during
attach.
* The onboard ethernet won't work until the PLL routines have been
fleshed out and shoe-horned into if_arge.
* The WMAC device glue (and quite likely the if_ath support)
hasn't yet been implemented.