added example for modelling of an instance
Merge branch 'master' of github.com:adhocracy/adhocracy-3
instance model example: enhance story.
splited MyInstance content in IInstance and IMyParticipationProcess
use titles for use cases
Merge branches 'master' and 'zodb_substance_d' of ssh://github.com/adhocracy/adhocracy-3 into zodb_substance_d
Merge branch 'zodb_substance_d' of ssh://github.com/adhocracy/adhocracy-3 into zodb_substance_d