compress: upgraded to AudioCompress 2.0

Copied sources from
http://beesbuzz.biz/code/audiocompress/AudioCompress-2.0.tar.gz

[mk: created this patch under fluffy's name and fixed some gcc
signed/unsigned comparison warnings]

src/normalize.h

@@ -28,7 +28,7 @@ void initNormalization(void);
 
 void finishNormalization(void);
 
-void normalizeData(char *buffer, int bufferSize,
+void normalizeData(void *buffer, int bufferSize,
 		   const struct audio_format *format);
 
 #endif /* !NORMALIZE_H */