- 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

Add kernel functions for 80-bit long doubles. Many thanks to Steve and
Bruce for putting lots of effort into these; getting them right isn't
easy, and they went through many iterations.

Submitted by: Steve Kargl <sgk@apl.washington.edu> with revisions from bde