Add the helpers property to the Handlebars module

handlebars/handlebars-tests.ts

@@ -80,3 +80,5 @@ Handlebars.registerHelper('fullName', (person: typeof context.author) => {
 });
 
 var escapedExpression = Handlebars.Utils.escapeExpression('<script>alert(\'xss\');</script>');
+
+Handlebars.helpers !== undefined;

handlebars/handlebars.d.ts

@@ -18,6 +18,7 @@ declare module Handlebars {
     export var Utils: typeof hbs.Utils;
     export var logger: Logger;
     export var templates: HandlebarsTemplates;
+    export var helpers: any;
 
     export module AST {
         export var helpers: hbs.AST.helpers;