[packagekit] Fix show percentage in Katja backend during download

[Richard Hughes]

On 8 December 2014 at 00:52, Sasa Ostrouska <casaxa at gmail.com> wrote:
> I believe that dividing by 2 the total tasks and have the percentage shown
> when downloading up to 50% and when installing the other part from 50% up to
> 100% is wrong.

The PackageKit spec says (and the clients expect) that a transaction
goes from 0% to 100% once, so typically it will do something like
this:

0% setup
10% downloading
20% downloading
30% downloading
40% downloading
50% downloading
60% downloading
70% installing
80% installing
90% cleanup
100% done!

If you want per-package percentage updates, there's the ItemProgress
signal that can be used.

Richard