add sockets wrappers

add sockets wrappers

2008-09-23  Paolo Bonzini  <bonzini@gnu.org>

	* lib/sys_socket.in.h: Do not implement rpl_setsockopt here,
	instead define prototypes for a full set of wrappers.  Ensure
	that Cygwin does not use the compatibility code, which is only
	for MinGW.
	* lib/winsock.c: New.
	* m4/sys_socket_h.m4: Compile lib/winsock.c if WinSock is being used.
	* modules/sys_socket: Add lib/winsock.c.

	* modules/poll-tests: Add errno and perror.
	* tests/test-poll.c: Use ioctl, not ioctlsocket.