A simple "page scaling" zoom à la Opera.
For now, it replaces the font scaling action, as the method names used for it in KHTML part are better suited to a real zoom (e.g. setZoomFactor).
Need to reintroduce pure font-scaling under another name...

Also introduce an alternate, non-blitting painting mode for being able to do fixed positioning again.

QScrollArea's quite a bit on the terse side, so there was no such thing ;(
Should fix widget jittering issues as a bonus.