Merge branch 'hotfix/fix_make_up_of_event_participants'

* hotfix/fix_make_up_of_event_participants:
  add locales
  add table of participants
Merge branch 'release/1.8.3'

* release/1.8.3:
  edit event/participant form
add test to admin events controller
edit urls
Merge branch 'hotfix/fix_admin_event_view' into develop

* hotfix/fix_admin_event_view:
  edit urls
  add test to admin events controller