Making PackageKit work with pirut and pup

[Richard Hughes <hughsient gmail com>]

I've come across a problem: The aim is for a user to be able to install
either:

* system-config-printer, pirut and yum
* system-config-printer, PackageKit and yum
* system-config-printer, PackageKit, pirut and yum

Unfortunately system-config-printer hardcodes:

Requires: pirut

when it should probably either
"Require: /usr/sbin/system-install-packages" or require some other
identifier that both PackageKit and pirut could provide.

I don't think PackageKit can just "Provide: pirut 1.1.4" as this
prevents us installing both pirut and PackageKit, nor can we just do
"Obsoletes: pirut, Provides: Pirut" in the PackageKit spec file.

If system-config-printer requires /usr/sbin/system-install-packages then
we should probably use alternatives so that PackageKit and pirut can
both provide this file.

Advice on how to patch s-c-p and also how to setup alternatives is
welcomed. I can't really submit PackageKit into the fedora repo until
this issue is fixed.

Thanks!

Richard.