* fhandler.h (fhandler_socket::recv): Remove method.

	* fhandler.h (fhandler_socket::recv): Remove method.
	(fhandler_socket::send): Ditto.
	* fhandler_socket.cc (fhandler_socket::recv): Ditto.
	(fhandler_socket::send): Ditto.
	(fhandler_socket::read): Delegate to fhandler_socket::recvfrom.
	(fhandler_socket::write): Delegate to fhandler_socket::sendto.
	(fhandler_socket::sendto): Check for null `to' address.
	* net.cc (cygwin_sendto): Check for zero request length.
	(cygwin_recvfrom): Ditto.  Fix signature, use void *buf.
	(cygwin_recv): Delegate to cygwin_recvfrom.
	(cygwin_send): Delegate to cygwin_sendto.