* src/modest-mail-operation.[ch]:

* src/modest-mail-operation.[ch]:
        * New mail operation "get_mime_part_size", asynchronous. This
          is used to show the mime part size in attachment view without
          blocking the UI when the size is big enough.
        * New mail operation "create_msg", asynchronous, that contains
          the old work done in save to drafts and send new mail for
          creating a valid TnyMsg instance to send. This is required
          because the operation can take long when the attachments are
          big enough. This operation is private.
        * Now send_new_mail and save_to_drafts use the new "create_msg"
          mail operation to avoid stalling the UI.
* src/widgets/modest-attachment-view.c:
        * Now we use the new mail operation for getting the attachment
          size. This way we don't block on attaching big files or
          from slow folders (as shared folders). We also remove the
          old synchronous implementation.
* src/modest-tny-msg.[ch]:
        * Now the constructors get a GList of attachments, not a (really
          fake) GSList.
* src/modest-ui-actions.c:
        * Now the save to drafts action does not remove the old draft
          itself, as it's now done internally in the mail operation. We
          also provide the edit window.
* src/maemo/modest-msg-edit-window.c:
        * We don't hang looping when there's an error in mime parts.
        * Now we check if the widget is visible on clipboard owner
          handler to prevent crashes on calling the handler after
          destroiying and before finalizing.

pmo-trunk-r2676