- added 2 config vars (`totp_two_step_login_active`, `totp_two_step_login_redirect`)
- changed `login()` to set session data if totp is required and two_step_login is active and skip default
- fixed `control()` to check if totp verification is required, if required then it redirects to `totp_two_step_login_redirect`
- fixed `control()` to check if is_loggedin not with totp verification is required
- changed `is_allowed()` to check if totp verification is required, if required then it redirects to `totp_two_step_login_redirect`
- added 2 functions `verify_user_totp_code($totp_code, $user_id = FALSE)` & `is_totp_required()`
reference to #131 (tutorial follows)
REJack
37a731dbdb