oc-calendar: Add edit/delete own and Folder Contact/Owner sharing perm

By storing these custom MAPI roles in the ACL.

The extension field 'X-SOGO-COMPONENT-CREATED-BY' is used to store the
event creator when it is done from Outlook. It is the same field SOGo
uses when an event is created from a shared folder in the webmail.

The creator and the organizer/owner of the event can be different and it can
be used from external sources by checking the organizer field. This matches
the specification from [MS-OXOCAL] Section 1.1 which defines the organizer
as the owner or creator of the event.

OpenChange/MAPIStoreCalendarMessage.m

@@ -528,6 +528,16 @@ static Class NSArrayK, MAPIStoreAppointmentWrapperK;
   ASSIGN (sogoObject, newObject);
 }
 
+- (NSString *) creator
+{
+  return [[self _appointmentWrapper] creator];
+}
+
+- (NSString *) owner
+{
+  return [[self _appointmentWrapper] owner];
+}
+
 - (BOOL) subscriberCanReadMessage
 {
   NSArray *roles;
@@ -539,20 +549,6 @@ static Class NSArrayK, MAPIStoreAppointmentWrapperK;
           || [self subscriberCanModifyMessage]);
 }
 
-- (BOOL) subscriberCanModifyMessage
-{
-  BOOL rc;
-  NSArray *roles = [self activeUserRoles];
-
-  if (isNew)
-    rc = [roles containsObject: SOGoRole_ObjectCreator];
-  else
-    rc = ([roles containsObject: SOGoCalendarRole_ComponentModifier]
-          || [roles containsObject: SOGoCalendarRole_ComponentResponder]);
-
-  return rc;
-}
-
 - (void) _updateAttachedEvents
 {
   NSArray *allAttachments;
@@ -632,6 +628,7 @@ static Class NSArrayK, MAPIStoreAppointmentWrapperK;
   [masterEvent updateFromMAPIProperties: properties
                           inUserContext: [self userContext]
                          withActiveUser: activeUser
+                                  isNew: isNew
 	                       inMemCtx: memCtx];
   [self _updateAttachedEvents];
   [[self userContext] activate];