mention avm2 (flash 9) muxer in documentation and changelog

Originally committed as revision 11591 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -109,6 +109,7 @@ version <next>
 - Sun Rasterfile decoder
 - TechnoTrend PVA demuxer
 - Linux Media Labs MPEG-4 (LMLM4) demuxer
+- AVM2 (Flash 9) SWF muxer
 
 version 0.4.9-pre1:
 

doc/general.texi

@@ -52,6 +52,7 @@ library:
 @item AVI@tab X @tab X
 @item WAV@tab X @tab X
 @item Macromedia Flash@tab X @tab X
+@item AVM2 (Flash 9) @tab X @tab X
 @tab Only embedded audio is decoded.
 @item FLV              @tab  X @tab X
 @tab Macromedia Flash video files