[packagekit] Implementation of searchFiles in APT backend

[Matthias Klumpp]

Hello!
I'm the author of the Listaller toolset. [1]
This project uses PackageKit to communicate with the package management
system of the current distribution. It is essential for us to use
searchFile for not installed packages, so we can find the required packages
for a binary or script.
Unfortunately this function needs extra-data on Debian based distros (I
asked this some time ago [2]).
So I included an apt-file based workaround to our PackageKit interface, so
it now works. But I would like to see those option in PackageKit too,
because I don't like this hack.
I am not a very experienced Python programmer (I do not really like
Python), but I can program in C++. Would it be accepted if I build a patch
for the APT-Backend which uses the apt-file tool do detect the dependency,
if apt-file is present? Or should I better add the function directly to a
backend? (Apt-file is written in Perl, I never wrote any line in Perl)
(This would require a flag to activate download of apt-files's extra data)
Which backend is the "best" at time? We have the APT-Python backend and
APTCC. Last time I heard that APTCC will implement the changes made on
Debian's debconf very fast, also there is active development on this
backend. But APT is default on Kubuntu...
I hope you can help me with my questions!
Regards
 Matthias

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[1]: Listaller is an application management & install suite focused on
applications, not on packages like PackageKit.
The goal of this project is not make software management on Linux as easy
as on MacOS-X and cross-distribution. (look at Ubuntu: They invented
AppCenter, which only runs on Ubuntu/Debian)
[2]:
http://lists.freedesktop.org/archives/packagekit/2009-August/005277.html