Moved Traversal Client code over from old netplay

Moved over gui code for copying host code
added gui to netplay diag setup to switch between direct and traversal connection

Source/Core/Common/TraversalClient.h

@@ -0,0 +1,88 @@
+// This file is public domain, in case it's useful to anyone. -comex
+
+#pragma once
+#include <functional>
+#include <list>
+#include <memory>
+#include "Common/Common.h"
+#include "Common/Thread.h"
+#include "Common/TraversalProto.h"
+
+#include "enet/enet.h"
+
+class TraversalClientClient
+{
+public:
+	virtual ~TraversalClientClient(){};
+	virtual void OnTraversalStateChanged()=0;
+	virtual void OnConnectReady(ENetAddress addr)=0;
+	virtual void OnConnectFailed(u8 reason)=0;
+};
+
+class TraversalClient
+{
+public:
+	enum State
+	{
+		Connecting,
+		Connected,
+		Failure
+	};
+
+	enum FailureReason
+	{
+		BadHost = 0x300,
+		VersionTooOld,
+		ServerForgotAboutUs,
+		SocketSendError,
+		ResendTimeout,
+		ConnectFailedError = 0x400,
+	};
+
+	TraversalClient(ENetHost* netHost, const std::string& server);
+	~TraversalClient();
+	void Reset();
+	void ConnectToClient(const std::string& host);
+	void ReconnectToServer();
+	void Update();
+
+	// called from NetHost
+	bool TestPacket(u8* data, size_t size, ENetAddress* from);
+	void HandleResends();
+
+	ENetHost* m_NetHost;
+	TraversalClientClient* m_Client;
+	TraversalHostId m_HostId;
+	State m_State;
+	int m_FailureReason;
+
+private:
+	struct OutgoingTraversalPacketInfo
+	{
+		TraversalPacket packet;
+		int tries;
+		enet_uint32 sendTime;
+	};
+	
+	void HandleServerPacket(TraversalPacket* packet);
+	void ResendPacket(OutgoingTraversalPacketInfo* info);
+	TraversalRequestId SendTraversalPacket(const TraversalPacket& packet);
+	void OnFailure(int reason);
+	void HandlePing();
+	static int ENET_CALLBACK InterceptCallback(ENetHost* host, ENetEvent* event);
+
+	TraversalRequestId m_ConnectRequestId;
+	bool m_PendingConnect;
+	std::list<OutgoingTraversalPacketInfo> m_OutgoingTraversalPackets;
+	ENetAddress m_ServerAddress;
+	std::string m_Server;
+	enet_uint32 m_PingTime;
+};
+
+extern std::unique_ptr<TraversalClient> g_TraversalClient;
+// the NetHost connected to the TraversalClient.
+extern std::unique_ptr<ENetHost> g_MainNetHost;
+
+// Create g_TraversalClient and g_MainNetHost if necessary.
+bool EnsureTraversalClient(const std::string& server, u16 port);
+void ReleaseTraversalClient();