This patch addapts modest to the new API for TnyHeader in tinymail

This patch addapts modest to the new API for TnyHeader in tinymail
(offering dup methods instead of get methods for obtaining strings).
* src/gnome/modest-msg-edit-window.c,
  src/gnome/modest-msg-view-window.c,
  src/widgets/modest-details-dialog.c,
  src/widgets/modest-attachment-view.c,
  src/widgets/modest-header-view.c,
  src/widgets/modest-mail-header-view.c,
  src/modest-tny-msg.c,
  src/modest-ui-actions.c,
  src/dbus_api/modest-dbus-callback.c,
  src/modest-tny-folder.c,
  src/modest-email-clipboard.c,
  src/maemo/modest-msg-edit-window.c,
  src/maemo/modest-platform.c,
  src/maemo/modest-msg-view-window.c,
  src/modest-formatter.c,
  src/modest-search.c,
  src/modest-tny-send-queue.c:
        * Use dup instead of get for TnyHeader strings.

Other changes:
* src/gnome/modest-account-settings-dialog.c:
        * Proper shadow for some tabs.
        * Use save password attribute properly.

pmo-trunk-r4347