Remove unnecessary prefixes from ipa-pwd-extop files
Add OTP support to ipa-pwd-extop

During LDAP bind, this now plugin determines if a user is enabled
for OTP authentication. If so, then the OTP is validated in addition
to the password. This allows 2FA during user binds.

    https://fedorahosted.org/freeipa/ticket/3367
    http://freeipa.org/page/V3/OTP