This basically allows to report operation from a Job inside the usual
progress monitor of the WizardDialog.

Change-Id: I5221484c6eda5731bd39c1dd5bdb0c3a4546b3da
Signed-off-by: Mickael Istria <mistria@redhat.com>
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>