Hey,

As projects evolve and become larger, multi module architecture become a crucial ability.
I think that incorporating a new code generator for modules would solve this problem.

For example:

ng g module components
ng g module demo-app
ng g module editor-app

npm run start-demo-app
npm run test demo-app
npm run lint components

I saw material2 implements this kind of functionality, and I was able to recreate it by following these steps:

1. karma-test-shim.js - appPaths is modified to cover all modules
2. angular-cli-build.js - Angular2App is built and returned based on the environment variable.
3. multiple tsconfig.ts directories under src/.

What do you think?