Create password reset ajax method

[arroyo]

create an ajax endpoint for password reset
update model to support password reset
model should send an email to the user with the new password

[arroyo]

there is an old forgotPassword() method in MailGun model...it should be moved out of that class and renamed to resetPassword. The original implementation of mail is not very good and was copied from an internal code base. There is a new issue to update mail #45