(CONNECT_PENDING): Ditto.
(CONNECTED): Ditto.
(class fhandler_socket): Add member `had_connect_or_listen'.
Add member functions `is_unconnected', `is_connect_pending' and
`is_connected'.
* fhandler_socket.cc (fhandler_socket::connect): Set member
`had_connect_or_listen' according to return code of WinSock
call.
(fhandler_socket::listen): Ditto.
* net.cc (cygwin_getsockopt): Modify SO_ERROR return value in
case of socket with pending connect().
* select.cc (peek_socket): Only add socket to matching fd_set
if it's not "ready". Call WINSOCK_SELECT only if at least one
socket is in one of the fd_sets.
(start_thread_socket): Only add socket to matching fd_set
if it's not "ready".
(fhandler_socket::select_write): Set write_ready to true also
if socket isn't connected or listening.