Adds a UI for accepting Discord join requests in Dolphin

also did these things
fixed crash from joining user that isn't hosting via a direct connection
current game stat can now pass to override the current game in config
uses ip endpoint from dolphin.org

Source/Core/DolphinQt/DiscordHandler.h

@@ -0,0 +1,43 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+// Note using a ifdef around this class causes link issues with qt
+
+#include <list>
+#include <thread>
+
+#include <QObject>
+
+#include "Common/Flag.h"
+
+#include "DolphinQt/DiscordJoinRequestDialog.h"
+
+#include "UICommon/DiscordPresence.h"
+
+class DiscordHandler : public QObject, public Discord::Handler
+{
+  Q_OBJECT
+public:
+  explicit DiscordHandler(QWidget* parent);
+  ~DiscordHandler();
+
+  void Start();
+  void Stop();
+  void DiscordJoin() override;
+  void DiscordJoinRequest(const char* id, const std::string& discord_tag,
+                          const char* avatar) override;
+  void ShowNewJoinRequest();
+signals:
+  void Join();
+  void JoinRequest();
+
+private:
+  void Run();
+  QWidget* m_parent;
+  Common::Flag m_stop_requested;
+  std::thread m_thread;
+  std::list<DiscordJoinRequestDialog> m_request_dialogs;
+};