Before this patch, we were looking for the size of the current Mode
in the Output object of the config that is passed to Config::setConfig
which either can or can't have the wanted Mode.

This has been kinda working so far because and ONLY because in
Generator (from kscreen/kded) we use the currentConfig as the base for
the config that we are generating, so all modes are included.

CCMAIL: dvratil@redhat.com

BUG: 320537
BUG: 321708
BUG: 321699
FIXED-IN: 1.0.1