Serve scaled images

[jkrehm]

Not sure how feasible this is, but on the list pages we limit the size of the images. That means we could be scaling a huge image down to a small size, but devices still need to store the huge image in memory. That's especially a problem on an under-powered device like a Kindle.

[jkrehm]

Possible solutions:

• http://agschwender.github.io/pilbox/
• https://python-pillow.org/ + https://github.com/wobeng/zappa_resize_image_on_fly

[jkrehm]

Also: https://stackoverflow.com/questions/273946/how-do-i-resize-an-image-using-pil-and-maintain-its-aspect-ratio