[raknet] Add TCPInterface class

* Adds TCPInterface ctor
* Adds `TCPInterface::Receive()`
* Adds `TCPInterface::HasLostConnection()`

raknet/TCPInterface.cpp

@@ -0,0 +1,28 @@
+// TODO: Implement TCPInterface.cpp
+
+#include "TCPInterface.h"
+
+TCPInterface::TCPInterface()
+{
+}
+
+Packet* TCPInterface::Receive( void )
+{
+	if (isStarted==false)
+		return 0;
+	return incomingMessages.ReadLock();
+}
+PlayerID TCPInterface::HasLostConnection(void)
+{
+	PlayerID *out;
+	out = lostConnections.ReadLock();
+	if (out)
+	{
+		lostConnections.ReadUnlock();
+		return *out;
+	}
+	else
+	{
+		return UNASSIGNED_PLAYER_ID;
+	}
+}