- 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

Update macros for multiple ABI support from NetBSD.
Also update SZREG define in ucontext

Using svn cp rather than cp to copy these files over had the benefit
of preserving their history. It had the problem that it also copied
over mergeinfo data. Since we're retiring the projects/mips branch,
I'm removing the svn:mergeinfo property from them all.

Submitted by: jhb

Merge from projects/mips to head by hand:

Copy over new cdefs.h..

Bring in cdefs.h from NetBSD to define ABI goo.

Obtained from: NetBSD