Complete refactoring to move Recipes into Items

* Changed "version" to "dataVersion" in data format
* Changed the "modName" and "modVersion" fields on the ModVersion
  class to remove the "mod" prefix and changed the data format to
  match
* Change the Stack class to use the itemSlug instead of the item
  itself
* Update the ModVersion and ModPack classes to include methods for
  recording a correspondence between slugs and names. Update code
  which displays items from stacks to use these methods to determine
  display names.
* Add a reference from Recipe back to the item it creates

src/scripts/models/mod_pack.coffee

@@ -29,6 +29,16 @@ module.exports = class ModPack extends BaseModel
             if modVersion.hasRecipe name
                 modVersion.enabled = true
 
+    findItem: (itemSlug, options={})->
+        options.includeDisabled ?= false
+
+        for modVersion in @modVersions
+            continue unless modVersion.enabled or options.includeDisabled
+            item = modVersion.items[itemSlug]
+            return item if item?
+
+        return null
+
     findItemByName: (name, options={})->
         options.includeDisabled ?= false
 
@@ -39,6 +49,16 @@ module.exports = class ModPack extends BaseModel
 
         return null
 
+    findName: (slug, options={})->
+        options.includeDisabled ?= false
+
+        for modVersion in @modVersions
+            continue unless modVersion.enabled or options.includeDisabled
+            name = modVersion.findName slug
+            return name if name
+
+        return slug
+
     gatherRecipeNames: (options={})->
         options.includeDisabled ?= false