fix #378, support multiple bouncing animations

--when two or more consequently launchers were bouncing
their animation was broken because they were changing
places. This patch catches these cases and provides
a proper way to show these animations.

plasmoid/package/contents/ui/task/animations/TaskLauncherAnimation.qml

@@ -135,7 +135,7 @@ SequentialAnimation{
             //trying to fix the ListView nasty behavior
             //during the removal the anchoring for ListView children changes a lot
             var previousTask = icList.childAtIndex(mainItemContainer.lastValidIndex-1);
-            if (previousTask !== undefined){
+            if (previousTask !== undefined && !previousTask.isStartup && !previousTask.inBouncingAnimation){
                 if (root.vertical) {
                     mainItemContainer.anchors.top = previousTask.bottom;
                 } else {

plasmoid/package/contents/ui/task/animations/TaskRealRemovalAnimation.qml

@@ -56,7 +56,7 @@ SequentialAnimation {
             //trying to fix the ListView nasty behavior
             //during the removal the anchoring for ListView children changes a lot
             var previousTask = icList.childAtIndex(mainItemContainer.lastValidIndex-1);
-            if (previousTask !== undefined){
+            if (previousTask !== undefined && !previousTask.isStartup && !previousTask.inBouncingAnimation){
                 if (root.vertical) {
                     mainItemContainer.anchors.top = previousTask.bottom;
                 } else {

plasmoid/package/contents/ui/task/animations/TaskShowWindowAnimation.qml

@@ -97,6 +97,20 @@ SequentialAnimation{
     }
 
     function execute(){
+        //trying to fix the ListView nasty behavior
+        //during the removal the anchoring for ListView children changes a lot
+        if (isWindow){
+            var previousTask = icList.childAtIndex(index-1);
+            var nextTask = icList.childAtIndex(index+1);
+            if (previousTask !== undefined && nextTask !== undefined && nextTask.inBouncingAnimation){
+                if (root.vertical) {
+                    mainItemContainer.anchors.top = previousTask.bottom;
+                } else {
+                    mainItemContainer.anchors.left = previousTask.right;
+                }
+            }
+        }
+
         //Animation Add/Remove (2) - when is window with no launcher, animations enabled
         //Animation Add/Remove (3) - when is launcher with no window, animations enabled
         var animation2 = ((((tasksModel.launcherPosition(mainItemContainer.launcherUrl) == -1)