Rename UserSiteDaoMixin to UserActionInfo....
Copy RdbSiteDao.scala to UserSiteDaoMixin.scala.
Break out UserSiteDaoMixin from RdbSiteDao.
Rename saveLogin() to tryLogin().
Don't let tryLogin() create new users

Do that in createUserAndLogin() instead.
Use new function NewUserData.identityNoId.
Save username.
Add DW1_USERS.CREATED_AT and EMAIL_VERIFIED_AT columns.
Move password from DW1_IDS_OPENID to DW1_USERS.