Send email to inform user that password is changed

[LinnaViljami]

Prerequisites

• [ ] Is it a bug?
• [x] Is it a new feature?
• [ ] Is it a a question?
• [ ] Can you reproduce the problem?
• [x] Are you running the latest version?
• [ ] Did you check for similar issues?
• [ ] Did you perform a cursory search?

Description

It would be good to notify the user if his/her password has been changed (reset or changed). This improves security. Notification could be used via email

Expected behaviour

When the user resets or changes the password successfully email is sent to user.