Critpath auto-generation

[Josh Boyer]

Hi All,

Should have the necessary gunk fixed up in the buildrawhide script and rel-eng
git repo to do autogeneration of a critpath.txt file finshed today.

We had discussed having the file stored in the same place as depcheck, which
is under the logs/ directory for rawhide.  I think that's fine, but the goal
there was to have a static URL for critpath.txt and, well, that won't be the
case if we put it there.  The /mnt/koji/mash/rawhide symlink is a link to
/mnt/koji/mash/rawhide-<date>/development/ so the 'logs' directory is omitted.

Since it seemed like we didn't want to put the critpath.txt file into the
mirrored content of rawhide, we could either not worry about the static
location and still put it under the logs dir.  Or we could create a new
/mnt/koji/mash/critpath.txt symlink that points to
/mnt/koji/mash/rawhide-<date>/logs/critpath.txt or $other_idea.

Let me know where you want the file to go.  I'll post a patch with the changes
before pushing it to the repo.

josh