Huge thumbnails, instant high quality redraw, + thumnail siz

[Defenestration]

The MP version only supports thumbnails up to 1024x1024. Can you bring back huge thumbnails support of 2048x2048, as in the original XnView. Maybe have a checkbox next to thumbnail slider, so huge thumbnails support can be enabled/disabled easily.

Can you display a tooltip when the thumbnail slider is clicked/dragged, showing the current thumbnail size.

Redraw thumbnails immediately while thumbnail slider is dragged, rather than after mouse button released. If high quality thumbnails is enabled, then display high quality while size being changed. Modern computers are fast enough that immediate redraw is not a problem. If you wanted to support older/slower computers, you could always make this immediate redraw optional.