Additional uninstalled package dpkg-query output

Before, we assumed that any package that was available but uninstalled
would yield the following output:

    $ dpkg-query -W -f "${Status}\n${Version}" package-name
    dpkg-query: no packages found match package-name

Turns out it's also possible to get this:

    $ dpkg-query -W -f "${Status}\n${Version}" package-name
    unknown ok not-installed

The debian packaging code now looks for both patterns, and treats either
as representing an uninstalled package.
Merge branch 'feature/dpkg-query' into develop

* feature/dpkg-query:
  Additional uninstalled package dpkg-query output