(fhandler_socket::set_sun_path): New method.
(fhandler_socket::get_sun_path): Ditto.
* fhandler_socket.cc (fhandler_socket::fhandler_socket): Initialize
sun_path to NULL.
(fhandler_socket::~fhandler_socket): Free sun_path if needed.
(fhandler_socket::set_sun_path): New method.
* net.cc (cygwin_bind): Set sun_path to path of local socket file.
(cygwin_getsockname): Add code to return correct sockaddr for unix
domain sockets.
