We don't need to call prepareGeometryChange if the geometry will not
change, this mistake end up with a new paint event that will paint for
nothing.
This should be backported into 4.3
svn path=/trunk/KDE/kdelibs/; revision=997763
still to come:
* don't paint when zoomed, replace with tool strip instead
* respect available area during drag
* smarter positioning (right now it just loads the saved position whenever it needs to reposition)
svn path=/trunk/KDE/kdelibs/; revision=884072
edges, rendering the right bits of the arc.
this now is used by the containment to render a non cutted toolbox when
there is a panel on top or on right
and to put the toolbox on the left with RTL layouts
svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=853991