Porting done by clazy.
I've been slowly going through all of Plasma, but a lot remain.
There's a combo of:
This breaks the KDE4 compilation of breeze style (of course !)
So if this patch is to stay, then one should officially drop the kde4 support (or make a branch for it).
In that case, much more code can go (a lot of QT Version ifdefs, some CMake magic, etc.)
Otherwise, the kstyle part of this patch at least, should be reverted.