Reset password

[mkhumml]

As a teacher I want to be able to reset my password so that I can change it for safety reasons.

Acceptance criterias:

• To change the password, the "reset password" button has to be pressed at the login
• Therefore you should be able to enter the username and e-mail address used at the registration
• Hitting the submit button should send an e-mail with a randomly created password
  • If the username and e-mail aren't used from one user there should be an error message
  • While hitting the button, the randomly created password should replace the old one in the DB

[sebastian15038]

finished, but Email cannot be send from localhost only when it is hosted on a server