* fhandler.h (fhandler_termios::line_edit): Add parameter to return
	written bytes.
	* fhandler_termios.cc (fhandler_termios::tcinit): Fix formatting.
	(fhandler_termios::line_edit): Return bytes actually written.  Write
	in 32 byte chunks in non-canonical mode to reduce number of WriteFile
	calls.  Don't just eat unwritten bytes in case of an error condition.
	Especially, don't report them back to the caller as written.
	* fhandler_tty.cc (fhandler_pty_slave::read): Disable code reducing
	the number of bytes read from the pipe to vmin.  Add comment.
	(fhandler_pty_master::write): Convert ret to ssize_t type.  Just call
	line_edit once, not in a loop once for each byte.  Return bytes written
	as returned by line_edit.
	* fhandler_termios.cc (fhandler_termios::line_edit): Fix fatal typo in
	bytes_read pointer checks.