Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import foremost from pkgsrc-wip.  Packaged by Lubomir Kundrak.

Foremost is a program to recover files based on their headers and
footers.  Foremost can work on image files, such as those generated by
dd, Safeback, Encase, etc, or directly on a drive.  The headers and
footers are specified by a configuration file, so you can pick and
choose which headers you want to look for.