[packagekit] Storing meta-information in files

[Richard Hughes]

I want to be able to provide the OSX feature:

Installed by:  Richard Hughes
Installed date: 07/09/2007

when you click the package name details. If we have no data (most of
the system installed stuff) then we just get nothing. We can't get
this from the backends, and so I'm proposing to store that sort of
meta-information in
/var/db/PackageKit/$package_id/{installed_by,when_installed}.

So questions:
* Is this sane? Is it even useful?
* How do I store dates and names in a per-system localised way? epoch?
* Is there anything else we should be storing?

Richard