Support for console-based interaction.

This file includes the interface to the console IO, tty style.

Refer also to the readline library.

Functions:

1. static Int prompt(USES_REGS1):

1. static Int promp/1(USES_REGS1):

1. bool Yap_DoPrompt(StreamDesc *s):

1. int console_post_process_read_char(int ch, StreamDesc *s):

1. bool is_same_tty(FILE f1, FILE f2):

1. static Int is_same_tt/2(USES_REGS1):

1. void Yap_ConsoleOps(StreamDesc *s):

1. int ConsolePutc(int sno, int ch):

1. int ConsoleGetc(int sno):

1. static Int ensure_prompting(USES_REGS1):

1. void Yap_InitConsole(void):