glebfm@ asked what to do with new package lists: whether these
belong to features, or to distributions themselves.  This question
is actually open and up for discussion but there are guidelines
that can and should be written down already; and so they were.

Added pkgdups utility reference as well.

The bin/pkgdups.sh script comes from m-p-d in considerably optimized
form and is to be used with the pkglist files of interest passed
as its arguments to produce a "hall of duplicates" among those.

The tagged lists received some updates along the rescue image lines,
most of those are actually inspired by http://rescuecd.pld-linux.org/
and to lesser extent a few articles on rescue/recovery/forensics
software -- so some newcomers are even employed already.