UrlGenerator support of alternate web server ports

As is anything using getRootUrl in UrlGenerator does not support running on a server with an alternate port. It drops the port from the url. After changing getRootUrl from getting its url from $this->request->root() to $this->request->getBaseUrl() this issue no longer occurs. For example, a Redirect::to('/login') from http://localhost:8080/ currently generates http://localhost/login. With this patch it generates http://localhost:8080/login as expected.