Added support for several frameworks + refactoring

Hi,
I added support for Knockout, Ember, Handlebars, Mustache, Angular and CoffeeScript (if the application includes the compiler). I've also changed the Backbone icon to the actual Backbone icon. I've migrated the manifest file to version 2. I've also merged the version and framework detection logic (I've now realized that it could be refactored even better but I'll leave it as it is for now). I've also split some html files containing js into two (e.g. popup.html into popup.html and popup.js) as now, Google disallows execution of inline javascript.