autopkgtest virt servers copied into tree

Hi. I have discovered that reprotest has a copy of the autopkgtest virt server implemnetations, in reprotest/virt. As the original author of the autopkgtest virt protocol, and much of that code, it's nice to see my stuff in use.

But, can you explain why you found it expedient to copy the code, rather than just call it?

Perhaps we should split them out of Debian's autopkgtest.git and make them a standalone thing. (Possibly we should change the name too.)