Pkgdepend

This is PR #8 rebased on top of master

I have not tested this yet because I am currently in merge hell for my own branches. I would have liked to make these changes on top of the template branch; that would have made it much easier to merge this on my own branches, but it is impossible because template is horribly out of sync with master (which I think should be fixed, I'm open to discussing some strategies to do that later)

I can't really test this without getting it merged on our branch with the proper pkg server settings etc. I'm going to do that and report back. This PR is thus preliminary at this point.