Both KCMs had a hard coded default which is obviously bad. Instead we
now calculate a useable implicitWidth and implicitHeight and use this
as the minimum size for the KCM. Which means we need also track changes
to these two root object properties and update the QWidget container
accordingly.
BUG: 332518
BUG: 332519
REVIEW: 117079
Let's try getting the KCM a little bit less scary by properly
hiding everything the user doesn't have to care about. The prominent
desktop effects KCM only contains the list of all the effects which
can be configured and nothing else. Only exception is the disabled
check after failed GL to make this easier for the user.
All the "advanced" settings are moved into a new KCM called
"Compositing" which is put under the hardware component in
systemsettings. This contains all advanced settings including
* whether compositing is enabled at all
* backend
* animation speeed
* scale filter
* unredirect fullscreen
* color correction
REVIEW: 116648
