Add an APIchanges note regarding the new rtp hinting flag

backport r23180 by mstorsjo


Originally committed as revision 23241 to svn://svn.ffmpeg.org/ffmpeg/branches/0.6

doc/APIchanges

@@ -12,6 +12,9 @@ libavutil:   2009-03-08
 
 API changes, most recent first:
 
+2010-05-18 - r23161 - lavf 52.63.0 - AVFMT_FLAG_RTP_HINT
+  Add AVFMT_FLAG_RTP_HINT as possible value for AVFormatContext.flags
+
 2010-05-01 - r23002 - lavf 52.62.0 - probe function
   Add av_probe_input_format2 to API, it allows ignoring probe
   results below given score and returns the actual probe score.