Add love.audio.getOutputDevice(s).

src/modules/audio/null/Audio.cpp

@@ -211,6 +211,15 @@ void Audio::resumeContext()
 {
 }
 
+std::string Audio::getOutputDevice()
+{
+	return "";
+}
+
+void Audio::getOutputDevices(std::vector<std::string> &/*list*/)
+{
+}
+
 
 } // null
 } // audio

src/modules/audio/null/Audio.h

@@ -89,6 +89,9 @@ public:
 	void pauseContext();
 	void resumeContext();
 
+	std::string getOutputDevice();
+	void getOutputDevices(std::vector<std::string> &list);
+
 private:
 	float volume;
 	DistanceModel distanceModel;