Fix Release Makefile Targets for WebWorkers

[jvilk]

WebWorkers use a function called importScripts to import other JavaScript files into itself. This works fine for our development release -- import some needed files, define require in terms of importScripts, etc. But our compressed release builds are different. We'll have to remove calls to importScripts in the release build, and we'll have to change the Makefile to make both a compressed version of the frontend logic and the backend logic.

We'll have to address this before we can ship a WebWorker release build.

[jvilk]

The doppio library is separate from the frontend now, so we could potentially do this now. Here's what would be required:

• BrowserFS needs to properly support proxying file system requests across the WebWorker boundary.
• Doppio needs to proxy console input across the WebWorker boundary.
• Doppio still needs to operate properly in a non-WebWorker environment. This is easy to do if the input/output abstractions (for file system and console interactions) use the same APIs.

[jvilk]

I just noticed that this isn't the main WebWorker issue. This is no longer an issue, since RequireJS works in a WebWorker.

http://requirejs.org/docs/api.html#webworker