- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

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.