term-ostream: Prepare for robustness through signal handling.

term-ostream: Prepare for robustness through signal handling.

* gnulib-local/lib/term-ostream.oo.h (ttyctl_t): New type.
(term_ostream_create): Add tty_control argument.
* gnulib-local/lib/term-ostream.oo.c (term_ostream_create): Likewise.
* gnulib-local/lib/term-styled-ostream.oo.h: Include term-ostream.h.
(term_styled_ostream_create): Add tty_control argument.
* gnulib-local/lib/term-styled-ostream.oo.c (term_styled_ostream_create):
Likewise.
* gnulib-local/tests/test-term-ostream.c (main): Use TTYCTL_AUTO.
* gettext-tools/src/color.c (print_color_test): Likewise.
* gettext-tools/src/write-catalog.c (msgdomain_list_print): Likewise.