Use the jsonfield as requirement
Added form field for multiple creation of new participants. Fixed #178.
Merge pull request #1174 from ostcar/json_field

Use the jsonfield as requirement
Merge pull request #1175 from normanjaeckel/MultipleParticipantsForm

Added form field for multiple creation of new participants. Fixed #178.
Added AbsoluteUrlMixin and used it in any model.

cleaned up get_absolute_url() in some models