- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Break out the AR71XX config file into _BASE and board specific
bits.

The ROUERSTATION and RSPRO variants contain:

* the board specific bits (eg the RTC for RSPRO, later on it'll
include the GPIO/LED definitions);
* the boot specific bits (eg, on-board flash, usb flash, etc).

For now the AR71XX_BASE file contains the common board config,
drivers and net80211/ath wireless drivers.

I'll follow this up with config files for the other boards I
have (eg the Ubiquiti LSSR71, as well as some Mikrotik boards
that use the AR71XX and atheros reference boards) which will
be quite easy to do now.