• Added composable conversions: You can now set composable: true for a Conversion, which makes the Conversion no longer "own" the Output. This allows you to add additional tracks manually, or have multiple conversions target the same output, useful for combining multiple files into one.
• Conversions can now be paused using the pauseSignal option on the execute method
• Conversions can now be stepped forward deliberately using the until option on the execute method