N#20027 PDF Reader crashes on selecting read only option in the details dialog box.

N#20027 PDF Reader crashes on selecting read only option in the details dialog box.

* hildon-widgets/hildon-file-details-dialog.c:
        (change_state): Fixed assertion that was causing problems
        (check_validity): New function: We now automatically close the
        dialog if the displayed file is removed.
        (handle_focus): Callback removed:
        (init): Now using correct gtk way to bind container and adjustment
        together. Not the previous callback.
        (set_property): Connecting/disconnecting new handlers (for
        change_state).
        (finalize): disconnecting new handler.