- Update MediaInfo to store all discovered audio streams in audio_streams
- Retain independent stream metadata and decoder state for MP4/MOV and Matroska/WebM
- Update audio_placement_specs to allocate successive tracks via ensure_audio_tracks
- Isolate clip rendering to read assigned audio stream rather than replaying stream 0
- Bump project schema to v13 with backwards compatibility for legacy v12 projects
Resolves#312Fixes#200Fixes#315