fixes #5

vue always throws a render error, even if we include a test for user.steeringUser
before comparing user.steeringUser.is_superuser.

so we moved it to the js logic and use a separat modules array for superusers

For vue-devtools see https://github.com/vuejs/vue-devtools

* deactivate superuser entries for standard users
* consistent naming

Merge branch 'feature-showmanager-superuser' of gitlab.servus.at:autoradio/dashboard into feature-showmanager-superuser