[packagekit] Merging a ton of new code

[Richard Hughes]

Guys,

I'm about to merge a ton of new code. Right from the inception of the
DBUS API I wasn't happy about returning the tid from the new method, as
this meant we couldn't do fast sync methods or return async errors.

I think we are hitting the create->connect race for some backends, where
the finished signal is send before the connect. I've reworked the API to
do a two step init (like HAL) where we request a tid, connect out
callbacks, and do the method. This means we can send async callbacks
from the sync method. This is a good thing, and was blocking the 0.1.0
release.

Both PackageKit and gnome-packagekit are affected as I've also really
simplified the client library (PkTaskClient+PkTaskMonitor->PkClient) so
expect a little instability for a few days. Please recompile both, and
report any problems to the list if you get new crashers or warnings.
I'll push to fd.o tmw if there are no problems.

Thanks.

Richard.