Draft: demux/mkv: Integrate MatroskaJS GotoAndPlay and LogMsg Command
The new Matroska Script 2 specification is being written with the name MatroskaJS. This MR intends to Integrate GotoAndPlay and LogMsg among the new commands.
At the same time it will integrate Duktape, an embeddable, ES5 compatible ECMAScript engine which will be used to interpret MatroskaJS.