Small fix to the zoom slider bar, the old sliderMoved(int) signal is just fired when...

Small fix to the zoom slider bar, the old sliderMoved(int) signal is just fired when the user pressed a mouse button and drags the slider. It is however possible to change the slider position by clicking into it or (when focus follows mouse is enabled) by hovering on top of the slider and scrolling the mouse wheel. The zoom state was currently not updated in the latter 2 cases.

svn path=/trunk/KDE/kdebase/apps/; revision=868815