Add example for dnd in a listbox with a listmodel

[jsparber]

This is an example for implementing a queue or anything where the user can reader a list via dnd. This includes also some animation for hidding and showing rows

[jsparber]

I still need to add more comments

[sdroege]

Nice :) I'll review once the comments are there, let me know!

[sdroege]

@jsparber What's the status of this? Do you plan to update it? :) Would be nice to get this merged as nothing really is missing here apart from some comments from what I understand?

[sdroege]

@jsparber any updates? :)