Revert deprecation of AVFrac structure. Attempts to replace AVFrac have turned

out to be unsatisfying and confidence in AVFrac has been restored.

Originally committed as revision 16441 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/avformat.h

@@ -208,7 +208,7 @@ static inline void av_free_packet(AVPacket *pkt)
 */
 typedef struct AVFrac {
     int64_t val, num, den;
-} AVFrac attribute_deprecated;
+} AVFrac;
 
 /*************************************************/
 /* input/output formats */