Bug 1100915 - [Usage][Refactoring] Use LazyLoader to load views. r=salva

Good test but I would prefer to split into several cases. Anyway, I would want to know you opinion about this. Let's check for moving styles from the panel to the head (it suffices asserting parent is head) and check for duplicates into another. And I'm wondering if activation is even needed as you can put scripts and links where you want and they should be interpreted by the moment they are in the DOM. Can you try removing _activation code_ to see what happens?