Mask MS bit of class to indicate a unicast response to mDNS

dns.parser.js

@@ -143,6 +143,10 @@ pdns.unpack = function (ab) {
     total += 2;
     q.byteLength = total - ototal;
 
+    // mDNS uses the MS bit of class to request a unicast response
+    q.unicastResponse = (q.class & 0x8000) !== 0;
+    q.class &= 0x7fff;
+
     q.className = classes[q.class];
     q.typeName = types[q.type];