* Added 'return' to goHome() calls in actions
* Changed $_POST to Yii::$app->request->post()

Revert "Fixes #1856: The default CSS class for hint generated by `ActiveField` is changed to `help-block`"

This reverts commit 7ae4695d.

Just a minor PHPDocs change. In the advanced application there is no such thing as "app\models".

Removed error-block HTML class and related styles and used Bootstrap3 standard practice about errors instead

to allow specific styling
also fixed an issue with gridview sort indicator css.

fixes #1000

Fixes #1597: Added `enableAutoLogin` to basic and advanced application templates so "remember me" now works properly

Backend should be always totally closed for indexing by search engine robots

Modified application templates so when trying to log in when already logged in it just redirects to homepage instead of throwing exceptions

- 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".