portability fixes, fixed UDP phantom port bug, fixed --version-intensity crash, changed mass_dns to give warning rather than error if cannot find dns servers

scan_engine.cc

@@ -3092,6 +3092,14 @@ static bool get_pcap_result(UltraScanInfo *USI, struct timeval *stime) {
 	    hss->target->v4sourceip()->s_addr != ip->ip_dst.s_addr)
 	  continue;
 	
+	/* Sometimes we get false results when scanning localhost with
+	   -p- because we scan localhost with src port = dst port and
+	   see our outgoing packet and think it is a response. */
+	if (probe->dport() == probe->sport() && 
+	    ip->ip_src.s_addr == ip->ip_dst.s_addr && 
+	    probe->ipid() == ip->ip_id)
+	  continue; /* We saw the packet we ourselves sent */
+
 	newstate = PORT_OPEN;
 	goodone = true;
       }