#81 modal form client code
#81 handling callback after successful submit
#81 client code for adding group talk in modal
js style fixes
modal title controlled from view
use of EventGroupSerializer + fatal typo fix
network error handler for modal form
Merge pull request #83 from ox-it/issue-81

Issue 81
#58 PersonEvent model enhancing person - event relation
using constants instead hardcoded strings for roles
helper properties on Event model for filtering people by role
imports cleanup
imports cleanup
#58 explicit role when adding speaker
#58 removing references to speaker
Merge pull request #85 from ox-it/issue-58

Issue 58
Merge branch 'master' into update-old-talks

* master:
  #58 removing references to speaker
  #58 explicit role when adding speaker
  imports cleanup
  imports cleanup
  helper properties on Event model for filtering people by role
  using constants instead hardcoded strings for roles
  #58 PersonEvent model enhancing person - event relation
  network error handler for modal form
  use of EventGroupSerializer + fatal typo fix
  modal title controlled from view
  js style fixes
  #81 client code for adding group talk in modal
  #81 handling callback after successful submit
  #81 modal form client code
Added TODO re pending update to data model