Fixed isBrowser check to use window.document instead (#319)

* Fixed isBrowser check to use window.document instead

* Simplified isBrowser check

* Removed function from isBrowser

Author: emtencza

api/WebApi.ts

@@ -42,8 +42,7 @@ import os = require('os');
 import url = require('url');
 import path = require('path');
 
-const isBrowser: boolean =(function(){return typeof window !== 'undefined' && this===window})();
-
+const isBrowser: boolean = typeof window !== 'undefined';
 /**
  * Methods to return handler objects (see handlers folder)
  */