- 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

Clean up, comment out non-base utilities, fix up comments.

Prodded by: hrs

Give users the ability to load a mac_bsdextended(4) ruleset on boot (defaults
to NO of course). Provide a basic ruleset file, rc.bsdextended, but allow
the filename to be overridden through rc.conf.

Discussed with: rwatson (awhile ago)