add on demand mode loading to cm.

src/deferred.js

@@ -0,0 +1,10 @@
+function deferred() {
+	var d = {};
+	var promise = new Promise(function (resolve, reject) {
+		d.resolve = resolve;
+		d.reject = reject;
+	});
+
+	d.promise = promise;
+	return Object.assign(d, promise);
+}