boolean - FALSE if cannot find the row. Calculate line number.
Change all callers.
(find_do_view_edit): Simplify. Get line number as argument.
(find_do_view): Close the dialog because it's modal and prevents
user from interacting with other windows.
(find_do_edit): Likewise.
(setup_gui): Enable panelize button. Improve look.
(find_panelize): New function. Implement panelize.
(find_file): Add support for view, edit and panelize commands.
(do_find): Likewise. Simplify.
(add_to_list): Block "select_row" signal until data is set.
directory row.
(add_to_list): Last argument is now boolean, FALSE for files,
TRUE for directories. Change all callers. Use item data for
the row of the last directory.
(select_row): Enable `view' and `edit' buttons for files only,
`change' button for all entries.
(setup_gui): Set selection mode to GTK_SELECTION_BROWSE. Make
`change' button inactive. Don't hide `view' and `edit' buttons.
(get_list_info): Look up directory using list item data.
Set g_find_dlg to NULL if it has been closed.
(kill_gui): Don't destroy already destroyed dialog.
(find_file): Onle read directory and filename if needed.
(do_find): Break loop on B_EXIT.
