As a follow up to the closed PR #5149 and in particular to the comments on the downside of the approach taken here is a new proposal:

• let's produce 2 UMD bundles:
  • core + RxJS
  • core + http + router + RxJS
• those bundles, being UMD, should be usable via a <script> tag and CJS-based tooling (WebPack etc.)
• those bundles won't contain "truly" external dependencies (zone, reflect-metadata, shims) - we are going to publish a separate file with those

@jeffbcross @robwormald @vsavkin - feel free to comment.

//cc.: @IgorMinar @rkirov