[UP-4149] Update the create tenant workflow to send a custom email instead of using the reset-password email.
Moved the guts of the code to generate and send that email to a more generic notification interface so that I could wire up 2 different impls and potentially eventually support other notification methods (eg. SMS).
[UP-4149] Updates based on code review comments.
[UP-4149]  Oops.  Forgot to update the spring wiring.  Fixed.
Merge pull request #353 from jhelmer-unicon/UP-4149_update_tenant_welcome_email_template

UP-4149 Differentiate new tenant from password reset emails.