- 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

Provide ability for printing and decoding pfsync(4) traffic. This
doesn't mean supporting IFT_PFSYNC (which I hope will eventually
die). This means decoding packets with IP protocol of 240 caught
on any normal interface like Ethernet.

The code is based on couple of files from OpenBSD, significantly
modified by myself.

Parser differentiates for four levels of verbosity: no -v, -v,
-vv and -vvv.

We don't yet forward this code upstream, because currently it
strongly relies on if_pfsync.h and even on pfvar.h. I hope that
this can be fixed in future.

Reviewed by: gnn, delphij