- 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

Remove headers copied from i386 and either useless or wrong on ia64.
An example of useless is bios.h. An example of wrong is msdos.h (due
to the use of long for 32-bit fields).

display.h cannot be removed because it's used by syscons. That header
however has no platform dependency and shouldn't really be here.

Removal if these headers may cause build failures in the ports tree.
It's the ports that need fixing in that case.

Tested with: buildworld, LINT

use __packed.

Add a few more files for the ia64 port.