TODO:
- Create a thread for showing the slides, one per monitor
 - This way, if slide thread pauses, can still get quit message
 - Also, allows for smoother playback on multiple montiros
- Rewrite resizing code to be much faster
 - Allow it to be interupted for quiting


- Double check code that cleans up threads better after quitting
- Clean up config code

Additional:
- Choice of speed, specific directories to show only
- Make mipmap downsampling code faster
- If not ready for next slide, 