Many big and small fixes

- fixed error on clearing data after seding them to endpoint;
- added support for obfuscating sensitive data, like settings,
passwords, etc. (fixed #4);
- request sends now more data, e.g. $_SERVER, $_POST, $_GET, $_COOKIE,
$_SERVER, etc. (fixed #3);
- removed unused debug option;
- adjusted Yii error handler to use latest client version;
- updated documentation;