Implement forgot password email functionality

[jrwdunham]

See:

• http://ruddra.com/2015/09/18/implementation-of-forgot-reset-password-feature-in-django/
• https://docs.webfaction.com/software/django/config.html
• https://docs.djangoproject.com/en/1.9/topics/email/

And maybe:

• http://stackoverflow.com/questions/730573/django-to-send-and-receive-email