"Fit image to window" option for slideshow

[Xip]

Thanks for the new version!

I like to have a small slideshow (not fullscreen) going when doing something else. However, it is very irritating that the window changes size constantly. So I suggest a "Fit image to window" option for the slideshow.

[Dreamer]

Support.

Maybe this option would be even better:

[x] Use custom/fixed size: [800] x [600]