- 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

opt_mac.h is no longer required for any of these modules, remove from
the dependencies.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, Network Associates Laboratories

Introduce support for Mandatory Access Control and extensible
kernel access control.

Hook up various policy modules to the kernel build.

Note that a number of these modules require futher entry point commits
in the remainder of the kernel to become fully functional, but enough
of the pieces are in place to allow experimentation.

Note also that it would be desirable to not build the mac_*.ko modules
if 'options MAC' is not defined in the kernel configuration, because
the resulting modules are not useful without the kernel option. There
doesn't appear to be precedent for a way to do this -- for example,
we allow ipfw.ko to be built even if 'options NETINET' isn't defined.
Suggests welcomed on the "best" way to do this.

Obtained from: TrustedBSD Project
Sponsored by: DARPA, NAI Labs