[packagekit] Showing the correct package versions

[Richard Hughes]

At the moment we show lots of versions of packages in the pk-application
UI, which is slightly confusing. If we have, for instance:

libnotify-0.5 in the repo "fedora"
libnotify-0.6 in the repo "updates"

and we have the latter installed.

If I search for all packages that are not installed (available) for
libnotify then I get back:

libnotify-0.5 (with a grey "uninstalled" icon)

If you then click the item, and click "install" most of the backends
will (correctly) barf.

For this instance, would a package return type of "old-version" be a
good idea? This would hide the install button (or make a "downgrade"
button appear).

I think we certainly need to distinguish between "available",
"installed", "old-version" in the backend and the UI. Comments?

Richard