* configure.in: Check for sys/select.h, termios.h, sys/socket.h,

* configure.in: Check for sys/select.h, termios.h, sys/socket.h,
netinet/in.h, and netinet/tcp.h.
* configure: Regenerate.
* config.in: Add those headers.
* main.c: Check for them.
(setup_tcp_console): Disable if no networking.
(main): Note missing networking or termios.
* mem.c: Check for those headers.
(stdin_ready): Disable if no termios.
(m32c_sim_restore_console): Disable if no termios.
(mem_get_byte): Disable console input if no termios.