Slideshow feature

[hzeller]

Given multiple images, timg right now displays them in sequence with a given wait-time -w.

It would be cool if there could be a transition effect (simplest: slide in, similar to the scrolling option).

Animated GIFs might be a problem as they might have a different timing between scroll-interval and their repetition interval. A good first implementation could just stop the animation, do the transition, and - if the next image is also an animated gif - start that animation there.

In this context, the different sizes of images have to be addressed as well. Since everything is in-place, they probably need black bars on the borders, with the image centered in the middle, to fill the given display space.