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 :)
In the form I have a hidden attribute field for cover_photo_token, with this I can set the uploaded cover_photo as a hidden attribute on the listing that we associate later.