- Re-use our audio decoder modules instead of using libavcodec directly.
  - No more dependance on libavcodec.
  (downmixing is currently broken + you have to force the ffmpeg codec for a52)
* modules/audio_filter/format.c:
  - PCM audio format conversion filter using the new common filter architecture.
* modules/audio_filter/converter/mpgatofixed32.c:
  - implements both the old and new filter architecture (ie. useable in the transcoder).
* modules/codec/ffmpeg/audio.c:
  - fixes and cleanup.

intf: Equalizer window in window menu
equalizer.m: presets should work now
equalizer.c, Modules.am, equalizer_presets.h: presets are stored in a separate file

    + New build system, using recursive makefiles. Due to the amount of code
      in VLC, this had become unavoidable.
    + Removed the check for OS X's stack size, since our automake targets are
      a lot less hungry now.
    + Ditto for Solaris's sed.
    + Since automake-1.6 is faster than 1.7, use it first if both are present.
  * m4/vlc.m4:
    + New AX_ADD_CPPFLAGS, AX_ADD_CFLAGS, AX_ADD_CXXFLAGS, AX_ADD_OBJCFLAGS
      and AX_ADD_LDFLAGS macros that do all the magic to detect possible
      modules and register their flags.
    + New AX_ADD_BUILTINS and AX_ADD_PLUGINS macros.
    + Some magic to generate vlc-config.
  * configure.ac:
    + Moved most code to the AX_ADD_* macros.
    + Explicitely added all target Makefiles.
  * modules/**/Modules.am:
    + Path to sources are now relative to Modules.am's directory level.

    reduce cluttering of the root directory.