For specific plunkers, e.g. "QuickStart (reboot edition)" PR #2762, that shouldn't have AppModule or main.ts
Rescinds the automatic bootstrapping and exclusion of `main.ts` in #2786 and #2756
Only autoBootstraps when `window.autoBootstrap === true`.
* plunker builder removes files and scripts not needed in plunkers (e.g., systemjs.config.js)
* no longer adds placeholder README.md (deemed a distraction)
* tag is now "Angular" instead of "Angular2"
* new plnkr.json "includeSystemConfig" option adds systemjs.config.js back; needed for testing plnkrs.
* incidentally changes comment "Polyfill(s)" to "Polyfills" in all index.html
Ward Bell
Jesús Rodríguez