Upgrade handlebars to 1.3.0.

This was "npm update handlebars" followed by copying
runtime.js into the static directory and restoring the
copyright header.

(imported from commit 69d30cbfcb3b776cdfdcffa17a87704540eab76a)

node_modules/handlebars/lib/handlebars.runtime.js

@@ -0,0 +1,31 @@
+/*globals Handlebars: true */
+module base from "./handlebars/base";
+
+// Each of these augment the Handlebars object. No need to setup here.
+// (This is done to easily share code between commonjs and browse envs)
+import SafeString from "./handlebars/safe-string";
+import Exception from "./handlebars/exception";
+module Utils from "./handlebars/utils";
+module runtime from "./handlebars/runtime";
+
+// For compatibility and usage outside of module systems, make the Handlebars object a namespace
+var create = function() {
+  var hb = new base.HandlebarsEnvironment();
+
+  Utils.extend(hb, base);
+  hb.SafeString = SafeString;
+  hb.Exception = Exception;
+  hb.Utils = Utils;
+
+  hb.VM = runtime;
+  hb.template = function(spec) {
+    return runtime.template(spec, hb);
+  };
+
+  return hb;
+};
+
+var Handlebars = create();
+Handlebars.create = create;
+
+export default Handlebars;