dpkg-query change to multiarch breaks getting installed packages

[Kyle Nitzsche]

We use dpkg-query to get the installed packages in some modes.

Currently a command like this:
cmd = ['dpkg-query', '-W', "-f=${Status} ${PackageSpec} ${Version},"]

However, at some point after 12.04, Ubuntu switched to multiarch and the PackageSpec field is no longer used by dpkg. (One can use binary:Package instead.)

The result is that getlicenses fails to obtain the list of installed packages and produces a null result set.

[Kyle Nitzsche (knitzsche)]

Loïc' Minier's MP [1] fixes this and handles both cases, before and after dpkg-query switches from PackageSpec to binary:Package.

I merge the change and have released 1.32 for saucy and 1.32~raring1 for raring.

[1] https://code.launchpad.net/~lool/getlicenses/fix-for-newer-dpkg-query-format/+merge/169508