Video Game engine now open source, moved to own repo

[zshall]

As part of the transition to Television Simulator 6.0, the video-game engine (a thin wrapper over Nostalgist.js) has been split into its own project. https://github.com/zshall/tvs-video-game-engine is where you can find it and build it for yourself.

Migration

If you previously used this channel syntax:

- number: -1
  video-game:
    game: flappybird.nes
    core: fceumm

You would now use:

- number: -1
  iframe:
    src: http://gcpw.art/tvs/engines/video-game
    options:
      game: flappybird.nes
      core: fceumm

Improving the TVS IFrame API

While annexing the video game engine from the mainline TVS codebase, the IFrame API has been extended with new features. Tvs.Terminate is a new message sent to deep integration IFrames so they can handle unloading code such as saving state when the channel is shut down. I'm hoping to continue to evolve the API to the point that we can have more capable 3rd party engines that can snap in via IFrames, including the ability to read channel and schedule information.