The media plugin can autoplay and autopause/autostop <audio> and <video> elements when entering and leaving a step.
Support for impressConsole: don't autoplay in preview window and play but mute clips in current window.
* Source files are under src/
* js/impress.js is now generated, but remains part of the repo (so it just works)
* npm run build
* build.js uses buildify node module
* Break out navigation and resize plugins from core src/impress.js file
