Edit user email and password

Hook the accountmanagement form with the backend.
A user's password or email can be changed using this UI component.

Frontend:
- The accountManagement directive handles submitting the forms
- As the Auth service we use the session service to pack the form data
- The directive has the _answer() and _error() hooks for handling changes
- The backend's message is flashed

Backend:
- horus.views.ProfileController is used
- it has an edit_profile() function which handles both email and password change
- Both edit_profile and changepassword client form is handled by this
- Checks user credentials