fixes

 * Added CSRF token generation and check functions
 * Added CSRF token check to `user_register`, `post_form` and `post_comment` when you are calling those function via the HTTP api
 * Fixes in custom fields
 * Session is now destroyed after password reset
 * Password reset hash is changed on user email change
 * Added validator class
 * Added `filter` parameter in the ORM
 * Fixes in search
 * Fixes in live edit
 * Added custom fields to "add to cart" module admin