* a 'standard' email layout which is an email to a user (user_mailer.html.erb/text)
* a 'from a user to another user' email layout (from_user_mailer.html.erb/text)
## user_mailer.html.erb
To use the user_mailer.html.erb layout, you must provide a title section, as well as the body.
Look at 'password_changed.html.erb' for an example.
## from_user_mailer.html.erb
To use the from_user_mailer.html.erb layout, you must provide a title section, photo_url section (photo of the person who sent the email), and a note section (any personalized note that the sender may have said, or boilerplate)
Look at 'friend_invitation.html.erb' for an example.
