Add APIchanges entry after the addition of AV_NE in r24814.

Originally committed as revision 24815 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:   2009-03-08
 
 API changes, most recent first:
 
+2010-08-17 - r24814 - lavu 50.24.0 - AV_NE()
+  Add the AV_NE macro.
+
 2010-08-17 - r24811 - lavfi 1.36.0 - audio framework
   Implement AVFilterBufferRefAudioProps struct for audio properties,
   get_audio_buffer(), filter_samples() functions and related changes.