Added Source:clone() and love.audio.newSource(source): creates a new (stopped) Source which has all of the settable state of the original.

Static sources don’t duplicate their OpenAL data buffer when cloned (resolves issue #319). Cloned streaming sources also clone the original Decoder.

src/modules/audio/null/Source.h

@@ -38,7 +38,7 @@ public:
 	Source();
 	virtual ~Source();
 
-	virtual love::audio::Source *copy();
+	virtual love::audio::Source *clone();
 	virtual void play();
 	virtual void stop();
 	virtual void pause();