[implemented] Better Gravatar usage .. or internal Plex avatar option

@oxguy3 said:
beckfield, try doing a refresh without cache (Ctrl+F5 on windows/linux, command+shift+R on mac). The avatars on the Switch Users screen seem to have really long cache times. My old Gravatar persisted for at least a week after I changed it before I finally thought to do Ctrl+F5, and that fixed it; perhaps the same applies to going from no Gravatar to a Gravatar.

I did that several times before I reported it, including manually clearing the cache. I’m running Firefox 41.0.1 on Linux Mint 17.1. I also have Pale Moon installed, which is a fork of Firefox from before their major UI change. It maintains its own cache, and I don’t use it very often, and it’s showing the same thing.