HTML Widgets; widget.UI.Grid; Data binding enhancements

The widget.UI.Grid's InitialiseRow method's event parameter now has an additional 'grid' property which references the parent grid.

Unlike many other controls, the Grid's event handlers do not have a 'self' parameter.

A GetVirtualClass method has also been added. This returns the class that the Grid has been bound to via its VirtualDataRefresh method.

These additions are particularly useful for dynamically created grid which can now access the collection they have been bound to, e.g.:

function grid_InitialiseRow(e) {
  var item = e.grid.GetVirtualClass()[e.row.listIndex];
  
  e.row.AutoBind(item);
}