First, get the activity, then the rest.
Merge commit '44bda057b3ef63bf626644dd612d1fa8a4d85b55' into activity
Adapting the tests to the new group loading.
Now we fetch only those members from the database that we want to display with an activity.
Move the activity loading to the API. Add the visitors to the activity.
Added a test for the function that was moved into activitiesAPI.
Merge pull request #478 from NicoleRauch/master

Anzeigen einer Aktivität aufgeräumt