Fix: IE8 compatiblity. Child rows couldn't be shown.

- The issue is related to the cloned nodes used for measurement. It
  appears that when the cloned element is removed (cloned using
  `cloneNode`) IE8 also removed the event handler from the original.
  Very not useful.
- Fix is to use jQuery to clone the table. Its going to be slower
  unfortunately, but it does at least seperate the elements properly.

js/dataTables.responsive.js

@@ -785,7 +785,7 @@ $.extend( Responsive.prototype, {
 		var columnWidths = dt.columns;
 		var clonedTable  = dt.table().node().cloneNode( false );
 		var clonedHeader = $( dt.table().header().cloneNode( false ) ).appendTo( clonedTable );
-		var clonedBody   = $( dt.table().body().cloneNode( false ) ).appendTo( clonedTable );
+		var clonedBody   = $( dt.table().body() ).clone( false, false ).empty().appendTo( clonedTable ); // use jQuery because of IE8
 
 		// Header
 		var headerCells = dt.columns()