Draft: Fixes in trackers

* Plane tracker can now be turned off in preferences
* Grid no longer stays in front of new objects

src/Mod/Draft/DraftSnap.py

@@ -631,6 +631,10 @@ class Snapper:
                     v.setCursor(cur)
                 self.cursorMode = mode
 
+    def restack(self):
+        if self.grid:
+            self.grid.lowerTracker()
+
     def off(self):
         "finishes snapping"
         if self.tracker: