Replaces yepnope.js with lazyload.js

Solves the caching and multi-load of the same file problems - adds a bit
of promise-based loading logic ontop of ll.js to ensure order and count

src/Umbraco.Web/UI/JavaScript/JsInitialization.cs

@@ -61,7 +61,6 @@ namespace Umbraco.Web.UI.JavaScript
             }
                 
                 return ParseMain(
-                    noCache,
                     result.ToString(),
                     IOHelper.ResolveUrl(SystemDirectories.Umbraco));
         }