Portsnap is now in the base system

About 12 hours ago I committed portsnap to HEAD.  From the commit log:

  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.

In particular, users who just want to keep their ports tree up to date
and don't want to do anything unusual (keeping a complete repository,
checking out old versions of the ports tree, getting themselves rooted
via a man-in-the-middle attack on cvsup, etc.) will probably find that
portsnap is a very useful tool.

There are several changes between the version in the ports tree and
the version I committed to HEAD, but the only one which most users should
notice is that the default location of portsnap's compressed snapshot has
moved from /usr/local/portsnap to /var/db/portsnap .

Please test.  The more people I see testing portsnap (I can see this via
the log files on the portsnap mirrors), the sooner it will get MFCed to
RELENG_6 and RELENG_5.  :-)

Colin Percival