IPFilter updated in HEAD

Hi,

I've just finished updating the in-tree source code for IPFilter from
4.1.13 to 4.1.23.  I'm hoping that for the first time I've managed to
do an import without breaking the build (although there are some new
compiler warnings from include files.)  Thanks to Pawel and ZFS for
making it easy to do testing of this through snapshots and rollback :)

As the cvs messages say, for a full list of changes see the HISTORY
file for IPFilter.

THe most significant change has been the move of the various "stats"
programs from being /dev/kmem grovellers to using ioctls so that they
can function on systems without /dev/kmem.

I'll be around if there are any problems...

Darren