Bug 941298 - Build changes for FFmpeg PlatformDecoderModule r=gps
Bug 941298 - Fix errors in content/media/fmp4 on Linux with clang and --enable-warnings-as-errors r=cpearce
Bug 941298 - FFmpeg headers for FFmpeg PlatformDecoderModule r=doublec

While FFmpeg function signatures tend not to change between versions of FFmpeg,
class layouts can change dramatically. We include libavcodec, libavformat,
and libavutil headers here so that we don't accidentally build against the wrong
binary interface.
Bug 941298 - FFmpeg PlatformDecoderModule for Linux r=doublec,cpearce