Catch up on video faster

Previously every (internal) update the decoder would advance 0 or 1 frame. Now
it will advance until it catches up. Like before, if it takes too many steps
(5) before catching up, it seeks instead. This should mostly mean seeking
forwards has less latency.

--HG--
branch : minor

src/modules/video/theora/TheoraVideoStream.h

@@ -83,7 +83,6 @@ private:
 
 	double lastFrame;
 	double nextFrame;
-	unsigned int lagCounter;
 
 	void parseHeader();
 	void seekDecoder(double target);