Enabled lazy load of poster images

This should make initial load of the movies page a little more
responsive for larger libraries. This can be used on any page loading
images.

dashboard-ui/thirdparty/jquery.unveil-custom.js

@@ -0,0 +1,62 @@
+/**
+ * jQuery Unveil
+ * A very lightweight jQuery plugin to lazy load images
+ * http://luis-almeida.github.com/unveil
+ *
+ * Licensed under the MIT license.
+ * Copyright 2013 Luís Almeida
+ * https://github.com/luis-almeida
+ */
+
+; (function ($) {
+
+    $.fn.unveil = function (threshold, callback) {
+
+        var $w = $(window),
+            th = threshold || 0,
+            retina = window.devicePixelRatio > 1,
+            attrib = retina ? "data-src-retina" : "data-src",
+            images = this,
+            loaded;
+
+        this.one("unveil", function () {
+            var elemType = $(this).get(0).tagName;
+            var source = this.getAttribute(attrib);
+            source = source || this.getAttribute("data-src");
+            if (source) {
+                if (elemType === "DIV") {
+                    this.style.backgroundImage = "url('" + source + "')";
+                } else {
+                    this.setAttribute("src", source);
+                }
+                if (typeof callback === "function") callback.call(this);
+            }
+        });
+
+        function unveil() {
+            var inview = images.filter(function () {
+                var $e = $(this);
+                if ($e.is(":hidden")) return;
+
+                var wt = $w.scrollTop(),
+                    wb = wt + $w.height(),
+                    et = $e.offset().top,
+                    eb = et + $e.height();
+
+                return eb >= wt - th && et <= wb + th;
+            });
+
+            loaded = inview.trigger("unveil");
+            images = images.not(loaded);
+        }
+
+        $w.scroll(unveil);
+        $w.resize(unveil);
+
+        unveil();
+
+        return this;
+
+    };
+
+})(window.jQuery || window.Zepto);