Resizable widget: resizer div has height 0 if <th> is empty

[ghost]

This can be easily be fixed by inserting a   inside the <th> instead of leaving it empty. I think it's worth mentioning this in the documentation :)

[Mottie]

Hi @gigib82!

Thanks! I'm thinking about rewriting the resizable widget to not add the resize element inside the header cell anyway ;)

[Mottie]

Added an "Important" note on the resizable demo page. Thanks again!