Clear form when object created
Specify related object in create form

* attributeList finds related objects and publishes a notification
  when it finds them (objectcreator.relationships.refresh)
* attributeList.js: listDone is a local variable in updateRelationships
* attributeList.js: listDone is a local variable in updateAttributes
* createForm: Subscribe to the objectcreator.relationships.refresh
  notification, and display additional createFormItem for each relationship
* createForm: Made addItem generic for both attributes and relationsihps