on openSUSE Factory and 13.2, PackageKit gets a bigger role due to the usage of
gnome-software, which also checks the repo metadata in the background if the
user types anything in the Overview screen (like: I want to start gimp, but
don't have it installed; g-software will find it and suggest it right away;
based on appstream data)

now, this makes PackageKit almost permanently around (we still have it
configured now to terminate after 15s idle, whenever you type anything in g-s,
it's being fired up).

Preferably, the PK daemon would not need to have to be terminated at all, but
would be allowed to run.

PK is built in a way that a lock is taken whenever an action on the DB happens
(refresh, get-updates, install,...) using ZyppJob::ZyppJob.
This should be enhanced to be able to share the lock with other things relying
on zypp.

As far as I've seen, zypper currently simply agressibly wants the packagekitd
to terminate, regardless if it's there in idle or having a lock on the DB. This
is a rude attack.