DNN4016 and DNN 4133 Bugs

NOTE:HAD DIFFICULTY INCLUDING NEW SQLDATAPROVIDER IN MY GIT COMMIT. MANUALLY ADDED FILE, IT IS IN THE INCORRECT LOCATION.

Fixes to enable an OAuth user to join more than one portal on one host.  Also fixes issue where a user may get a duplicate username error when the user has the same email prefix as another user with a different email domain.  (i.e. Joe@live.com and Joe@hotmail.com).