activities can now be created by every member and each member can edit her own activities
Merge branch 'hotfix'

# Via Andreas Leidig (1) and leider (1)
* hotfix:
  Fixing that any superuser can add new authentication to any user
Merge branch 'hotfix'

# Via Andreas Leidig (2) and leider (1)
* hotfix:
  FIX: sent mails don’t render txt on button
  no message
remove hidden field that’s not needed
when saving a newly created member, user’s profile must be deleted to assure reliable (de)serialization of user across sessions
Merge pull request #491 from leider/master

activities can now be created by every member and each member can edit h...