[packagekit] Minor change to Resolve() function in 0.5.x

[Richard Hughes]

I've made a small spec change in git master:
42a80c903522c3391da687baec3596283c7c2842

This specifies that applications can do Resolve("powertop") or, if the
whole package_id is known, Resolve("powertop;0.1.2;i386;repo") is also
valid.

This allows GUI clients to get the summary (short description) and
installed status of package_id, without playing games and hoping only
one package is installed with that name (which fails horribly with
packages like kernel and many others on multilib). In the GNOME tools
we were doing a kludge by looking at the data field of the package_id
to tell if a package is installed, which seems to fall down pretty
often.

I've changed the dummy backend to accept a package_id as well as a
package name. I'll do the yum backend tomorrow, and I would appreciate
if you backend guys could do your backends in the next two weeks or
so.

None of the GUI or console clients will need this functionality just
yet, but the glib2 library falls down pretty hard when it tries to do
clever things with packages. In 6 months or so (when the GNOME
applications are using glib2) then backends not providing this spec
addition are going to have pretty bare GUIs, and might not even work
at all. As always, comments welcome.

Richard.