made device enumeration lazy

made enumerator to first attempt aquire default device name by standard means,
then to fall back to read name from opened device
getRecordingDeviceCount removed for being redundant

--HG--
branch : minor-mic-input

src/modules/audio/null/Audio.cpp

@@ -144,19 +144,9 @@ float Audio::getDopplerScale() const
 	return 1.0f;
 }
 
-int Audio::getRecordingDeviceCount() const
+std::vector<love::audio::RecordingDevice*> *Audio::getRecordingDevices()
 {
-	return 0;
-}
-
-love::audio::RecordingDevice *Audio::getRecordingDevice(int index) const
-{
-	return nullptr;
-}
-
-int Audio::getRecordingDeviceIndex(love::audio::RecordingDevice *device) const
-{
-	return -1;
+	return &capture;
 }
 
 Audio::DistanceModel Audio::getDistanceModel() const