* maemo/modest-main-window.c:

* maemo/modest-main-window.c:
  - use mail_operation error handling capabilities when
   operation os removed from queue.
* modest-mail-operation.c:
  - folder_copy_async works fine now.
  - added a new private field, error_handler to perfomrs
    required operations during an error state.
* modest-ui-actions.c
  - use a mail operation with error handling capabilities
   to perform copy_async operation.
  - get message header from tree model, when message is
   deleted using toolitem of viewer view. (Fixes: #NB55370)

pmo-trunk-r1912