[packagekit] Reviewing use of internal-error

[Richard Hughes]

On Mon, 2008-03-24 at 20:32 -0400, Elliot Peele wrote:
> * DowngradeError
> * UpdatePinnedTroveError
> * DependencyFailure
> * DepResolutionFailure
> * EraseDepFailure
> * NeededTrovesFailure
> * InstallPathConflicts

Robin, could you please add these also? If you are busy, yell, and I'll
do them tomorrow.

Thanks.

Richard.