Allows the user to login only via email without reseting the password

In case the loginstyle is set to alternate and the user clicks choses option "I have no password"  the user is now able to login via email instead of requesting a new password.

routing.py
- added path to the "emaillogin" action in the user controller

user.py
- added perform_email_login method to the user controller.If the adhocracy.login_style is set to alternate it sends an email with an login link to the user
- Added emaillogin method to catch EmailLoginRepozeWho errors

Authentication.py
- Changed the Path action path to perform_email_login
- Added Email EmailLoginRepozeWho

created emaillogin.py
- Added EmailLoginRepozeWho controller

created login_email.html
- Informs the user that he got a new email