Avoid creating multiple paintables of the same image, lowering ram usage
Avoid processing already processed images
TODO:
Add a "dont cache" option. We really don't want to cache profile pics/banners. They change but the url stays the same, let libsoup handle their caching
Combine with #915
Increase maintenance timeout to probably 1 minute?
Use url hashes instead (same as #915)
More testing on the media viewer... maybe let libsoup handle that?
A way to update paintables so race conditions / updates don't break existing ones? Or maybe not inserting if it exists already?
:warning: WIP
Mostly discussed on #954
Bringing back the classic in-memory cache.
Benefits:
TODO: