Redesign the crafting page

This introduces the new crafting page design featuring a new vertical
layout and list display of all crafting steps. It also makes it easy
to move items between the have/need sections and even from each step
into your inventory (causing a new crafting plan to be created which
doesn't plan on making that item).

* Convert the `BaseController.hide` and `show` methods to be much
  more robust in the use of CSS transitions (using a timer in case a
  transition doesn't actually fire).
* Change `hide`/`show` to use events for communicating animation
  state instead of callbacks
* Convert several controllers to fire events for communication with
  parent controllers instead of accepting functions.
* Rewrite the `CraftPageController`, `CraftPage` model and related
  Jade/SCSS files to implement the new design.
* Alter the `InventoryController` and `StackController` to allow a
  variety of action buttons, and for the events from those action
  buttons to bubble up to parent controllers
* Add the `StepController` and its related model, template, and style
  sheet as part of the new craft page.
* Tweak the `ItemSelectorController` and related files to allow for
  a variety of styles for the launcher button

src/coffee/models/inventory.coffee

@@ -20,9 +20,6 @@ module.exports = class Inventory extends BaseModel
         attributes.modPack ?= null
         @clear()
 
-        Object.defineProperties this,
-            isEmpty: { get:-> @_itemSlugs.length is 0 }
-
     # Class Methods ################################################################################
 
     @Delimiters =
@@ -161,6 +158,14 @@ module.exports = class Inventory extends BaseModel
 
         return parts.join Inventory.Delimiters.Stack
 
+    # Property Methods #############################################################################
+
+    getIsEmpty: ->
+        return @_itemSlugs.length is 0
+
+    Object.defineProperties @prototype,
+        isEmpty: { get:@prototype.getIsEmpty }
+
     # Object Overrides #############################################################################
 
     toString: ->
@@ -185,7 +190,7 @@ module.exports = class Inventory extends BaseModel
         stack = @_stacks[itemSlug]
         if not stack?
             stack = new Stack itemSlug:itemSlug, quantity:quantity
-            @listenTo stack, Event.change, => @trigger Event.change, stack
+            @listenTo stack, Event.change, => @trigger Event.change, this
             @_stacks[itemSlug] = stack
             @_itemSlugs.push itemSlug
             @_sort()