- FFmpegReader info struct should not be initialized during Open() after it is initially populated - so our SetJson() method can properly override it's values
- FrameMapper Json() method should include it's mapped Reader JSON - even though it is not yet possible to read it back in yet
- New unit tests for Timeline ApplyJsonDiff, and verification that we can override FFmpegReader info struct (i.e. updating FPS, time bases, etc...)
- Some whitespace fixes