- 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

Build fixups for the new USB stack.

Remove dependency on dev/usb/usbdevs.h, in preparation for its
disappearing from the tree. We already were splitting the baby (using
the symbol for the vendor BROADCOM, but not for the device). Use
#defines for both.

Broadcom firmware loading module.. The actual firmware files will follow when
the legal status has been confirmed, in the meanwhile they can be
downloaded from the location in the README file.