- Remove OpenID support

For those not following along, this removes support for OpenID from SMF. The reason for this is that SMF only supports OpenID 1.1, which is an old standard that isn't supported anymore. The latest version of OpenID is "OpenID Connect", but implementing this would require either studying up on the new standard or using a third-party library, which in turn would further delay SMF for something that many people don't use anyway. It was decided the best option at this point is to remove support for the old standard and allow for mods to handle other authentication methods (Facebook, etc.).

Signed-off-by: Michael Eshom <oldiesmann@oldiesmann.us>