move text area to cursor only when cursor is moved

lib/ace/layer/cursor.js

@@ -175,6 +175,9 @@ var Cursor = function(parentEl) {
         if (overwrite != this.overwrite)
             this.$setOverite(overwrite);
 
+        // cache for textarea and gutter highlight
+        this.$pixelPos = pixelPos;
+
         this.restartTimer();
     };