Massive refactoring to clean up models

* Tweak style of quantity label in output box to be more visible
* Move data files for all mods under a directory for the specific
  version of the mod
* Add a `silent` property to the base model to prevent models which
  shouldn't be observed from emitting events
* Change the term "itemSlug" to just "slug" across the board
* Change all models so that they don't require their parent in their
  constructors and so that they don't automatically add themselves to
  their parents lists
* Remove a bunch of unnecessary event triggering
* Tighten up access to various lists of children across all models
* Refactor the guts of the V2 parser into an abstract base class so
  it can be used for other parsers in the future
* Remove a number of unused methods

src/scripts/models/item_page.coffee

@@ -41,7 +41,7 @@ module.exports = class ItemPage extends BaseModel
     _updateLocation: ->
         list = @plan.want.toList()
         if list.length is 1
-            itemSlug = if _.isArray(list[0]) then list[0][1] else list[0]
-            router.navigate "/item/#{itemSlug}"
+            slug = if _.isArray(list[0]) then list[0][1] else list[0]
+            router.navigate "/item/#{slug}"
         else
             router.navigate "/"