Use ffmpeg embedded aac encoder instead of libfaac

<extension point="command" target="org.nuxeo.ecm.platform.commandline.executor.service.CommandLineExecutorComponent">

    <command enabled="true" name="ffmpeg-tomp4">
      <commandLine>ffmpeg</commandLine>
      <parameterString> -i #{inFilePath} -s #{width}x#{height} -acodec aac -strict -2 -vcodec libx264 -v 0 #{outFilePath}</parameterString>
      <winParameterString> -i #{inFilePath} -s #{width}x#{height} -vcodec libx264 -v 0 #{outFilePath}</winParameterString>
      <installationDirective>You need to install ffmpeg from http://ffmpeg.org (apt-get install ffmpeg)
      </installationDirective>
    </command>
  
  </extension>