Issue #92: Initial work on making possible to edit referenced inline items.
Issue #92 : Adding a controller to referenced inline items.
Disabling auto opening form on inline reference fields just after adding a item.
Cleaning up data when canceling adding an inline referenced item.
Loading proper form for editing inline referenced items for polymorphic referenced types.
Fixing typo in context title.
Issue #92: Changing subform title to "Edit" when editing an inline referenced item.
Changing subform submit button label to  "Save".