Merge branch '542_temporary_urls' into 'master'

beat/web/accounts/api.py

...ounts/management/commands/clean_expired_temporary_urls.py

...b/accounts/management/commands/year_revalidation_users.py

beat/web/accounts/migrations/0012_accounts_temporary_url.py

...nts/migrations/0013_supervisee_rejection_temporary_url.py

beat/web/accounts/models.py

beat/web/accounts/templates/accounts/url_rejection.html

...web/accounts/templates/accounts/url_rejection_failed.html

.../accounts/templates/accounts/url_revalidation_failed.html

beat/web/accounts/templates/accounts/url_validation.html

...eb/accounts/templates/accounts/url_validation_failed.html

beat/web/accounts/tests.py

beat/web/accounts/urls.py

beat/web/accounts/views.py

beat/web/navigation/admin.py

beat/web/ui/registration/models.py

...plates/registration/mail.account_revalidation.message.txt

...stration/mail.account_revalidation_supervisor.subject.txt

...mail.supervisor_possible_supervisee_rejection.message.txt

...lates/registration/mail.supervisor_validation.message.txt