API for html-ing a site with only necessary resources

[joelgriffith]

There's enough meta-data inside of Chrome to generate a webpage with only the resources it uses. This is fairly easy to achieve with the css, but gets tricker with js as the API for interaction with those resources is different (and the file-size of JS can be quite large).

MVP would:

• Generate an asset of some kind (zip, gzip, tar) containing all the resources necessary.
• We would automatically trim out unused css or JS.
• Potentially make a lazy-loader where the remaining unused assets can be loaded async. This would help in getting time to first paint, but still preserve full functionality since it's hard to itemize all user cases.