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/scss/templates/craft_page.scss

@@ -7,20 +7,44 @@ All rights reserved.
 
 .view__craft_page {
 
-    & > div {
-        display: inline-block;
-        margin-top: 2em;
-        padding: 0 2em;
-        position: relative;
-        vertical-align: top;
+    .want.section {
+        .view__inventory {
+            position: relative; width: 100%;
+        }
     }
 
-    .view__inventory { width: 50%; height: 30em; }
+    .tools.section {
+        .options {
+            margin-top: 4em;
+        }
+    }
 
-    .view__crafting_table { width: 50%; height: 30em; }
+    .ingredients.section {
+        .need {
+            margin-top: 4em;
+        }
+    }
 
-    .want label {
-        position: absolute; top: 50%; left: 0.5em;
-        @include transform(translateY(-50%));
+    .instructions.section {
+        p {
+            font-size: $font-size-large;
+            margin-top: 1em;
+
+            &:first-child {
+                margin-top: 0;
+            }
+        }
+
+        ol {
+            margin: 2em 3em 0 3em;
+
+            li {
+                font-family: $font-family-normal;
+                font-size: $font-size-large;
+                line-height: $font-size-normal + 0.15em;
+                list-style: decimal;
+                margin: 0.66em 0 0 2em;
+            }
+        }
     }
 }