oath.py: remove debug code
accdb: add a @2fa.oath.window parameter
accdb: accept plain strings in @2fa.oath.psk
accdb: check type in OATHParameters.generate()
oath.py: add a Dynadot-specific version of HOTP & TOTP
accdb: add support for Dynadot TOTP
Merge branch 'wip/dynadot-otp'

Add support for Dynadot's failed attempt at OATH TOTP to `accdb`. It
uses the serial number in ASCII as the key, and a 60 second window
instead of 30, but an OATH-compatible hash & truncation method.