dont paint items when shadow is activated

--this way we gain a few cpu cycles because they
are not painted when the item is painted through
the Shadow qml item

containment/package/contents/ui/applet/AppletItemWrapper.qml

@@ -379,6 +379,8 @@ Item{
         anchors.topMargin: plasmoid.location === PlasmaCore.Types.TopEdge ? lowThickUsed : 0
         anchors.bottomMargin: plasmoid.location === PlasmaCore.Types.BottomEdge ? lowThickUsed : 0
 
+        opacity: appletShadow.active ? 0 : 1
+
         property int lowThickUsed: root.reverseLinesPosition ? root.thickMarginHigh : root.thickMarginBase
 
         //BEGIN states
@@ -514,6 +516,7 @@ Item{
 
     ///Shadow in applets
     Loader{
+        id: appletShadow
         anchors.fill: container.appletWrapper
 
         active: container.applet

plasmoid/package/contents/ui/task/TaskIconItem.qml

@@ -120,6 +120,7 @@ Item{
         width: parent.width
         height: parent.height
 
+        opacity: root.enableShadows ? 0 : 1
 
         //fix bug #478, when changing form factor sometimes the tasks are not positioned
         //correctly, in such case we make a fast reinitialization for the sizes