FFmpeg Concat Strategies

[piuggi]

• Create naming convention for files, will files be deleted or continually made new
• Create a file which FFmpeg will use to order and concat our video files
• Listen for callback and serve updated file to PlayerApp

[jmsaavedra]

done! passed initial tests, commit: https://github.com/incredibleMachines/30PP/commit/cc6a2025fcf5272f4744b1146c7453d09359572c