layout: better tween guard

Turning off fullscreen would desync `c.targetY` and `c.y`. Simply make the guard
robust by making sure they are synced before foregoing tweening. This should
work better than making sure that we're always syncing the target everywhere.

We also shouldn't need to tween when `widthChanged`, if the clone doesn't move
we should be able to activate the window. If the layout initiates a scroll
`moveDone` won't activate any windows anyways.

tiling.js

@@ -312,9 +312,8 @@ class Space extends Array {
                 }
 
                 let c = w.clone;
-                if (widthChanged ||
-                    c.targetX !== x ||
-                    c.targetY !== y) {
+                if (c.x !== x || c.targetX !== x ||
+                    c.y !== y || c.targetY !== y) {
 
                     c.targetX = x;
                     c.targetY = y;