Make the emulation stop asynchronous to prevent deadlocks.

This may expose bugs which relied on the Main Thread to be suspended in the stopping state.

Source/Core/Core/Core.h

@@ -39,6 +39,7 @@ enum EState
 
 bool Init();
 void Stop();
+void Shutdown();
 
 std::string StopMessage(bool, std::string);
 
@@ -81,4 +82,8 @@ void UpdateTitle();
 // the return value of the first call should be passed in as the second argument of the second call.
 bool PauseAndLock(bool doLock, bool unpauseOnUnlock=true);
 
+// for calling back into UI code without introducing a dependency on it in core
+typedef void(*StoppedCallbackFunc)(void);
+void SetOnStoppedCallback(StoppedCallbackFunc callback);
+
 }  // namespace