Solaris needs -lsocket and -lnsl and does not support gethostbyname2()

With these changes we build and work on solaris

lib/socket.c

@@ -84,7 +84,11 @@ iscsi_connect_async(struct iscsi_context *iscsi, const char *portal,
 	if (inet_pton(AF_INET, addr, &sin->sin_addr) != 1) {
 		struct hostent *he;
 
+#ifdef HAVE_GETHOSTBYNAME2
 		he = gethostbyname2(addr, AF_INET);
+#else
+		he = gethostbyname(addr);
+#endif
 		if (he == NULL) {
 			iscsi_set_error(iscsi, "Invalid target:%s  "
 					"Failed to resolve hostname.", addr);