Display a loading message

[ghost]

It would be nice if sortable-table could show a loading message when data is loading. Users love loading messages.
Maybe datasource could have a "loading" attribute and then sortable-table could show/hide a div or template depending of that attribute.
Thank you for sortable-table.

[stevenrskelton]

I've added a loading Boolean to sortable-table's attributes.

It can be used to do something externally, but I do plan on templating loading and empty scenarios sometime in the future.