Vmbuilder for Debian

As we needed it for one of our customers, I’ve started to add support for Debian to the Ubuntu VMBuilder. My changes are not merged into trunk yet, but you can get them by running bzr branch lp:~bzed/vmbuilder/debian. At the moment there is only support for Etch, I’ll add Lenny and Squeeze as soon as I find the time for it, probably next week - patches are welcome.