Few fixes/tweaks for the Cache app, but still a bit to go

Hey man,

Here are a few things I did to tweak the application. There's actually a few more things to do to make it more secure, but I figured I had already changed a lot of things already :)
I made a new method in the listings controller for uploading a photo, which means I needed to modify the existing one. I provide it a URL so it can submit it up, and it's a post request instead of patch.