Username email address part is case sensitive
|auth email lowerase easy-pickings
|Patch needs improvement:
I've discovered that create_user from User model manager (auth contrib module) lowercases newly created user's email address. The RFC document says, that only domain part of email address is case insensitive, so I think that lowercasing the username part is a bug. See RFC 821 and RFC 1035.
Please correct it, by lowercasing only domain name part of email address.