Add nascent version of the mod detail page

* Create a nascent version of the mod detail page
* Make the slug mandatory for Mod instead of name, and load the name
  from the data file
* Make the Feedback view universal on all pages
* Refactor the use of mod pack to have a single global object at the
  router level which is shared between pages. Further, make this one
  object load itself immediately and have it automatically load any
  activated mod version
* Refactor the use of Storage related to mod pack versions into the
  router as well.
* Add trace logging back in for events, but allow individual classes
  to suppress it (as opposed to actually supressing the events)
* Fix a bug in ModVersion.eachItem where it would suggest so-called
  items which are merely registered slugs without associated items

src/scripts/controllers/item_page_controller.coffee

@@ -20,7 +20,7 @@ Storage                 = require '../models/storage'
 module.exports = class ItemPageController extends BaseController
 
     constructor: (options={})->
-        options.model        ?= new ItemPage
+        options.model        ?= new ItemPage modPack:options.modPack
         options.imageLoader  ?= new ImageLoader defaultUrl:'/images/unknown.png'
         options.storage      ?= new Storage storage:window.localStorage
         options.templateName  = 'item_page'