Add a mechanism for automatically triggering package rebuilds if a package has been updated

[berolinux]

It would be great to have a way to make abf automatically rebuild some packages whenever another package is updated -- e.g. packages containing kernel modules (***ing nazividia-) need to be rebuilt whenever kernel-release is updated.

It would also be useful to make sure packages are rebuilt against libraries on soname bumps (e.g. automatically rebuild texlive and inkscape whenever poppler is updated -- people forget to do that too often).