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 :)
After you upload an image, let's update the text to say "Replace Photo", instead of keeping the "Upload Photo" text that appears when a cover photo is not uploaded.