refactoring

+ don't use global variables in partials, but pass them through
+ added some comments to public methods in javascript files
+ hopefully improved variable naming for better understandability
+ changed route "mediabrowser/edit" to "mediabrowser/inspector"
+ use class method instead of a class constant
+ keep line length below 100 characters
+ use single ticks as default
+ insert whitelines for haml instructions on the same level