Fix bugs in intra-site linking

* Refactor event handling in controllers to use a method to define
  the hash (and thereby allow inheritance)
* Refactor link handling so that links which should be handled by the
  router can be handled by the base class
* Change the router to throw out controllers for pages which aren't
  on-screen (and thereby avoid a lot of weirdness)

src/scripts/controllers/crafting_table_controller.coffee

@@ -84,7 +84,8 @@ module.exports = class CraftingTableController extends BaseController
 
     # Backbone.View Overrides ######################################################################
 
-    events:
-        'click .next':      'onNextClicked'
-        'click .prev':      'onPrevClicked'
-        'click .problem a': 'onReportProblem'
+    events: ->
+        return _.extend super,
+            'click .next':      'onNextClicked'
+            'click .prev':      'onPrevClicked'
+            'click .problem a': 'onReportProblem'