Also allows setting the "distro name" so that things that change the debootstrap signature will have a different tarball. This is being done in advance of a debian-upstart element to allow experimenting with debian and upstart. Change-Id: I1a558fdaf5924c65f1cced9f9bf29d73643c30af
Create an image based on Debian. We default to unstable but DIB_RELEASE is mapped to any series of Debian.
Note that the default Debian series is unstable, and the default
mirrors for Debian can be problematic for unstable. Because apt does
not handle changing Packages files well across multiple out of sync
mirrors, it is recommended that you choose a single mirror of debian,
and pass it in via DIB_DEBIAN_MIRROR.
Use of this element will also require the tool 'debootstrap' to be available on your system. It should be available on Ubuntu, Debian, and Fedora.