Add an entry to APIchanges for the addition of sws_convertPalette8ToPacked32 -24

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@23415 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

doc/APIchanges

@@ -12,6 +12,9 @@ libavutil:   2009-03-08
 
 API changes, most recent first:
 
+2010-06-01 - r31301 - lsws 0.11.0 - convertPalette API
+  Add sws_convertPalette8ToPacked32 and sws_convertPalette8ToPacked24
+
 2010-05-26 - r23334 - lavc 52.72.0 - CODEC_CAP_EXPERIMENTAL
   Add CODEC_CAP_EXPERIMENTAL flag.