* fhandler.h (fhandler_pty_master::tcgetpgrp): Declare.

	* fhandler.h (fhandler_pty_master::tcgetpgrp): Declare.
	* fhandler_termios.cc (fhandler_termios::tcgetpgrp): Only return
	valid pgid if tty is controlling tty.  Set errno to ENOTTY and
	return -1 otherwise.
	(fhandler_pty_master::tcgetpgrp): New function.  Return 0 for
	master side of pty if it's not the controlling tty of the process.