Refactor controllers and templates for user/admin views. Use right routers. Add become_admin and become_user debug controllers.
Do not redirect, send unauthorized.
Transform ObjectId to unicode for indexation.
Remove Account.test_cases_id.
Add TODOs.
Merge branch 'cbenz'

Conflicts:
	openfisca_web_ui/controllers/accounts.py
	openfisca_web_ui/model.py
Fix flakes8 errors.