cannot file bugs on source packages that have not been published

The distribution pillar object would be a great fit for distro-like projects that don't use soyuz but do want to use Launchpad. Currently only 'source packages published in series X' can have bugs filed on them (and this is a sane limit to allow both sourcepackage name reporting and prevent bugs being filed on deleted packages).

To permit non soyuz using distro-like projects to use the bug tracker we need them to be able to file bugs. One way would be to use the existence of a blessed branch in a series to trigger bugfiling for that (sourcepackagename,series) component. This could either be a replacement policy, or a unioned policy, depending on how it would impact Ubuntu.

Ubuntu currently has a problem with things that haven't been published yet being unable to have bugs filed on them, so the thinking is that it wouldn't affect them negatively - but an explicit check is worth doing.