Password recovery page

User enters his email and submit.
A new password is generated and hashed.
User table entry for this user is updated.
Password is sent by email to the user.

![pwdrecov](https://cloud.githubusercontent.com/assets/3430891/5136784/6999ffc2-70fc-11e4-942f-bb8d2003bb60.PNG)

You have `DatabaseError` directly available already, use it.