cucul_set_color() and cucul_set_truecolor() under the new names
cucul_set_color_ansi() and cucul_set_color_argb().
* Renamed cucul_get_color_name() into cucul_ansi_to_str().
int which shall be used as an UTF-32 character. We do not have any casting
problems due to the signedness of chars because all characters were
ASCII (ie. <= 0x7f) beforehands.