feat: serve and bundle using webpack2.

[mprobst]

Including using the Angular AoT compiler ngc.

This does not hook up ngc with webpack yet, so probably should not be merged yet.

[ogix]

I wonder why did you leave only one webpack entry? For tree shaking to work? And I see polyfills are not loaded. Aren't they necessary?

[mprobst]

@ogix if you have tree shaking working off a root, you don't really need multiple binaries anymore. It's nicer to start off from the one main.ts file and just include whatever it needs.

@gdi2290 as I said above, this PR had some issues and should probably not be merged yet, in particular no non-AoT development mode. At this point it might be easier to use one of Rob's webpack starters. I'd suggest rather rolling back.