Perform the following task in Codeignitor 3.11 or 4 (latest stable);

1. Create a login and user registration form. Login form - username, password and captcha Registration form - username(mandatory), email(mandatory), contact number(mandatory), address(optional), password (mandatory)

2. Dashboard should have a list of registered users and use datatable (latest stable) with ajax pagination functionality (datatable should not load all data at once).

3.User list add and edit functionality should be a single function.

4.Download user list in Excel, using PHP Excel library.