Advanced application enhancements.

- Turned on CSRF validation by default.
- Added access control for login, signup and logout for frontend application.
- Added access control for login, logout and index for backend application.
- YII_ENV is now defined for all applications.
- No trace is writted to logs if debug is turned off.
- Added default error view for frontend and backend.
- In frontend application captcha will always ask for "testme" if YII_ENV is defined as "test".

apps/advanced/environments/dev/yii

@@ -9,6 +9,7 @@
  */
 
 defined('YII_DEBUG') or define('YII_DEBUG', true);
+defined('YII_ENV') or define('YII_ENV', 'dev');
 
 // fcgi doesn't have STDIN defined by default
 defined('STDIN') or define('STDIN', fopen('php://stdin', 'r'));