Removed inappropriate overloads in 'jquery.gridster' and 'royalslider', fixed JQuery overload for 'data' in 'jquery'.

jquery.gridster/gridster-tests.ts

@@ -16,7 +16,7 @@ var options: GridsterOptions = {
 	}
 };
 
-let gridster: Gridster = $('.gridster ul').gridster(options).data('gridster');
+var gridster: Gridster = $('.gridster ul').gridster(options).data('gridster');
 gridster.add_widget('<li class="new">The HTML of the widget...</li>', 2, 1);
 gridster.remove_widget($('gridster li').eq(3).get(0));
 var json = gridster.serialize<SerializeData>();

jquery.gridster/gridster.d.ts

@@ -248,7 +248,3 @@ interface Gridster {
 	**/
 	disable(): Gridster;
 }
-
-interface JQuery {
-    data(key: "gridster"): Gridster;
-}