Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

s/MAN8/MAN/

Pointed out by: ru

Add portsnap to the base system. This is a secure, easy to use,
fast, lightweight, and generally good way for users to keep their
ports trees up to date.

This is version 0.9.4 from the ports tree (sysutils/portsnap) with
the following changes:
1. The experimental pipelined http code is enabled. No seatbelts
in -CURRENT. (^_^)
2. The working directory has moved from /usr/local/portsnap to
/var/db/portsnap (as discussed on -arch two days ago).
3. Portsnap now fetches a list of mirrors (distributed as DNS SRV
records) and selects one randomly. This should help to avoid the
uneven loading which plagues the cvsup mirror network.
4. The license is now 2-clause BSD instead of 3-clause BSD.
5. Various incidental changes to make portsnap fit into the base
system's build mechanics.

X-MFC-After: 6.0-RELEASE
X-MFC-Before: 5.5-RELEASE
X-MFC-To: RELENG_6, RELENG_5, ports
discussed on: -arch and several other places
"yes please" from: simon, remko, flz, Diane Bruce
thinks this is a great idea: bsdimp
Hopes he didn't forget any files: cperciva