[5/6] wsdapi: Add support for sending messages via UDP multicast.

[Vincent Povirk]

+    delay = rand() % (UDP_MAX_DELAY - UDP_MIN_DELAY + 1) + UDP_MIN_DELAY;

Using rand() for this doesn't seem very random, and it could interfere
with an application's use of rand().

+    /* Get size of buffer for adapters */
+    adapterAddresses = (IP_ADAPTER_ADDRESSES *) HeapAlloc(heap, 0, bufferSize);

Was this comment meant to be earlier?

Sending messages to every adapter in sequence, with a delay for each,
doesn't seem right.

+void terminate_networking(IWSDiscoveryPublisherImpl *impl)
+{
+    impl->publisherStarted = FALSE;
+
+    WSACleanup();
+}

It seems like this will call WSACleanup even when freeing an object
that was never used.