Doesn't seem like first and last name needs to be required

[jonespm]

This came up on the mailing list and I think this is where the problem is.

This needs first, last and email address defined. But if someone wanted to leave off either their first or last name, that seems like it should be fine. Having both of these filled in isn't required by Google, just having even one character in either First or Last name is good enough.

https://github.com/tsugiproject/tsugi/blob/5dd2a0af301c07fa81f75280a0f4a48148ca424d/login.php#L159