First draft of register-by-API
Clement does not know the gender
Bugfixes: API registration
Fix config loading in views
Login: update hash function, login init

The new hashing function is weaker but that is required for
commonication with subscription platform
Removed deprecated registration system

Removed forms, template, functions, etc.
Welcome email is sent by views.api
Registration fix
Gender asked in profile
Update style: forms, tables
Merge branch 'login-v2'

API registration is 100% ready
API functions left to implement:
- password update
- planning communication
Views bugfix: parens
Improved date & time experience

- System localization
- Use jinja filters everywhere, better filters