* include/cygwin/in.h: Drop including stdint.h. Move definition

	* include/cygwin/in.h: Drop including stdint.h.  Move definition
	of in_port_t and in_addr_t to top of file and use throughout. Use
	sa_family_t type where appropriate.
	(struct in6_addr): Change `unsigned char' to `uint8_t'.
	(struct sockaddr_in6): Add sin6_scope_id member. Add comments.
	* include/cygwin/socket.h: Include stdint.h.  Move definition of
	socklen_t to top of file.  Define sa_family_t.  Define struct
	sockaddr_storage as per SUSv3.
	* include/sys/un.h: Include cygwin/socket.h.  Use sa_family_t type.