With fractional scaling integer based logical geometry may not match
device pixels. Once we have a floating point base we can fix that. This
also is
important for our X11 scale override, with a scale of 2 we could
get logical sizes with halves.

We already have all input being floating point, this doubles down on it
for all remaining geometry.

- Outputs remain integer to ensure that any screen on the right remains
aligned.
 - Placement also remains integer based for now.
- Repainting is untouched as we always expand outwards
 			   (QRectF::toAdjustedRect().
 - Decoration is untouched for now
 - Rules are integer in the config, but floating in the adjusting/API
This should also be fine.

At some point we'll add a method to snap to the device pixel
grid. Effectively `round(value * dpr)  / dpr` though right now things
mostly work.

This also gets rid of a lot of hacks for QRect right and bottom which
are very
confusing.

Parts to watch out in the port are:
 QRectF::contains now includes edges
QRectF::right and bottom are now sane so previous hacks have to be
removed
 QRectF(QPoint, QPoint) behaves differently for the same reason
 QRectF::center too

In test results some adjusted values which are the result of
QRect.center because using QRectF's center should behave the same to the
user.