increase the number of maximum supported streams

[ami_stuff]

MAX_STREAMS 20 seems to be not enough, maybe increase it to 100?

libavformat/avformat.h:
#if FF_API_MAX_STREAMS
- #define MAX_STREAMS 20
+ #define MAX_STREAMS 100
#endif

​http://www.cccp-project.net/beta/test_files/%5BCCCP%5D_Mega_Weird_Audio_Test.mkv

C:\>ffmpeg -i C:\[CCCP]_Mega_Weird_Audio_Test.mkv
FFmpeg version git-N-29181-ga304071, Copyright (c) 2000-2011 the FFmpeg develope
rs
  built on Apr 18 2011 21:24:03 with gcc 4.5.2
  configuration: --enable-gpl --enable-version3 --enable-runtime-cpudetect --ena
ble-memalign-hack --enable-avisynth --enable-bzlib --enable-frei0r --enable-libo
pencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --
enable-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger
 --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enabl
e-libx264 --enable-libxavs --enable-libxvid --enable-zlib --cross-prefix=i686-w6
4-mingw32- --target-os=mingw32 --arch=x86_32 --extra-cflags=-I/home/kyle/softwar
e/ffmpeg/external-libraries/win32/include --extra-ldflags=-L/home/kyle/software/
ffmpeg/external-libraries/win32/lib --pkg-config=pkg-config
  libavutil    50. 40. 1 / 50. 40. 1
  libavcodec   52.120. 0 / 52.120. 0
  libavformat  52.108. 0 / 52.108. 0
  libavdevice  52.  4. 0 / 52.  4. 0
  libavfilter   1. 79. 0 /  1. 79. 0
  libswscale    0. 13. 0 /  0. 13. 0
[matroska,webm @ 01CEC000] Too many streams
C:\[CCCP]_Mega_Weird_Audio_Test.mkv: Not enough space

[reimar]

API/ABI was changed during major bump to support "arbitrary" number of streams.
Your suggestion would have broken ABI and thus would not have been possible without a major version increase either.