transcoding: sanitize resolution
transcoding: copy transcoding paramaters from a playlist GET request to the url inside the generated m3u8 file
transcoding: added intial support for VP8 (matroska container only)
transcoding: added initial support for vorbis. might suffer from sync problems when frames are dropped earlier in the pipe line
muxer: added initial support for the webm container
transcoding: avoid resetting thread_count to default value (zero).