* tuiIO.c (tui_putc): New function to print one character.
(printable_part): New function from readline/complete.c.
(PUTX): New macro, likewise.
(print_filename): New function, likewise.
(get_y_or_n): New function, likewise and adapted for TUI.
(tui_rl_display_match_list): New function from readline/complete.c
and writes on TUI command window.
(tui_setup_io): Install or remove the readline hook
rl_completion_display_matches_hook so that completion is written
directly in TUI command window instead of in the TUI pipe.
(tui_initialize_io): Use #ifdef TUI_USE_PIPE_FOR_READLINE for the
TUI redirection pipe.
(tui_getc): Likewise for call to tui_readline_output.
(tui_readline_output): Likewise for function.
* tui.c (tui_rl_startup_hook): Always take care of gdb prompt.