[packagekit] don't allow partial updates

[Jesse Zhang]

Hi,

Currently gpk-update-viewer allows users to check/uncheck updates, but
it doesn't make sense in some cases, e.g. for the conary backend. It's
fairly possible to break systems if an update-system is partially
done.

Some details in the bug Description here,
http://issues.foresightlinux.org/jira/browse/FL-2394.

Another problem that may be related is that, even "If the user applies
all of the updates, the backend tries to apply them individually as
single update jobs in the order the GUI has presented them.", instead
of one 'update-system'. But I haven't checked if it's the case.

Is it easy to solve?

jesse