I need to keep the generated sources out of source control.

I could use `node_modules`, but that's is a bad idea as explained in the e-mail by @sam-github.

What options are remaining:

 - Create a new directory where to put the generated source files, e.g. `html5/generated`.
 - Add more structure to `build`, e.g. `build/bundle` for browserify output, `build/config` for generated sources.
 - Keep the generated files in `html5/` and use a naming convention that allows a simple .gitignore rule, e.g. `html5/browser.datasources.js` and `html5/browser.models.js` can be ignored by rule `html5/browser.*.js`.

Thoughts?