[packagekit] Adding a filter to GetRepoList

[Richard Hughes]

In fedora we will want to filter out some repos that the user won't
normally want to see, for instance *-debuginfo and *-source.

The ultimate use case is a repo viewer with a few entries:

[X] Fedora 9
[X] Livna 9
[ ] DAG 8.92
----------------------
[ ] Show detailed repository information

And if the last checkbox is enabled, then the -source, -debuginfo and such are
also shown for people that know what to do with them.

It's a pretty trivial patch to add a filter parameter to the GetRepoList
method (most of the other methods have filters) and I think I can do it
without breaking any of the backends.

Is this a good idea? I see worst case, an ignored extra parameter.

Richard.