Intervention revocation

* adds Revocation model to interventions/models.py
* adds revocations to interventions detail view
* fixes duplicated ids in html includes
* refactors controls for detail view into included template files (controls.html)
* reduces max length for payment transfer notes from 1000 to 200
* adds RevocationAdmin to intervention/admin.py
* adds new form for adding a Revocation to an intervention's legal_data
  * only one revocation per intervention possible
  * removes add button in case of an existing revocation
* adds revocation routes to intervention app
* renames document field in Document model into file for more clarity
* adds/updates translations

konova/sub_settings/django_settings.py

@@ -38,8 +38,8 @@ ALLOWED_HOSTS = []
 LOGIN_URL = "/login/"
 
 # Session settings
-SESSION_COOKIE_AGE = 30 * 60  # 30 minutes
-SESSION_SAVE_EVERY_REQUEST = True
+#SESSION_COOKIE_AGE = 30 * 60  # 30 minutes
+#SESSION_SAVE_EVERY_REQUEST = True
 
 # Application definition
 
@@ -149,7 +149,7 @@ LANGUAGE_CODE = 'de'
 USE_THOUSAND_SEPARATOR = True
 
 DEFAULT_DATE_TIME_FORMAT = '%d.%m.%Y %H:%M:%S'
-DATE_FORMAT = '%d.%m.%Y'
+DEFAULT_DATE_FORMAT = '%d.%m.%Y'
 
 TIME_ZONE = 'Europe/Berlin'