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/controllers/header_controller.coffee

@@ -81,7 +81,7 @@ module.exports = class HeaderController extends BaseController
             addThisUrl = '//s7.addthis.com/js/300/addthis_widget.js#pubid=ra-54f3c9717b2e530d'
             $('body').append "<script async src=\"#{addThisUrl}\"></script>"
 
-        @_itemSelector = @addChild ItemSelectorController, '.view__item_selector',
+        @_itemSelector = @addChild ItemSelectorController, '.view__item_selector.search',
             modPack:     @modPack
             onChoseItem: (itemSlug)=> @_goToItem(itemSlug)