Updating session helper constructor to fix failing tests in Controlle…

…r::render() integration tests.

cake/libs/view/helpers/session.php

@@ -31,6 +31,19 @@
  */
 class SessionHelper extends AppHelper {
 
+/**
+ * Constructor.  Starts the session if it has not already been started
+ *
+ * @param View $view View instance for this helper
+ * @param array $settings Settings for the helper.
+ * @return void
+ */
+	public function __construct(View $view, $settings = array()) {
+		parent::__construct($view, $settings);
+		if (!CakeSession::started()) {
+			CakeSession::start();
+		}
+	}
 /**
  * Used to read a session values set in a controller for a key or return values for all keys.
  *