Code cleanup part #1: move all the services and directive JS code in the app.js file into its own files

static/js/directives/ng-if-media.js

@@ -0,0 +1,15 @@
+/**
+ * Adds an ng-if-media attribute that evaluates a media query and, if false, removes the element.
+ */
+angular.module('quay').directive('ngIfMedia', function ($animate, AngularHelper) {
+  return {
+    transclude: 'element',
+    priority: 600,
+    terminal: true,
+    restrict: 'A',
+    link: AngularHelper.buildConditionalLinker($animate, 'ngIfMedia', function(value) {
+      return window.matchMedia(value).matches;
+    })
+  };
+});
+