remove eval functions in background and MangaElt

The background page and popup load without errors
Fix a bug in popup too... event was bind before DOM load...
Manga list can't be seen because AMR can't eval mirror implementations
so mirrors are unrecognized... Need to load them via script tag in https
remove a br in the popup

@braiam can you use two spaces as tabulation ??
change repository to https for CSP 2.0

AMR community repository must be in https to ensure manifest 2.0
compatibility.
TODO : include script in page instead of eval(js file content);