This change installs HttpModule with ServerModule, and overrides bindings to
service Http requests made from the server with the 'xhr2' NPM package.
Outgoing requests are wrapped in a Zone macro-task, so they will be tracked
within the Angular zone and cause the isStable API to show 'false' until they
return. This is essential for Universal support of server-side HTTP.
Note that the duplication in tsconfig.json files will be fixed in a followup CL now that we have tsconfig inheritance
BREAKING CHANGE: Angular 4 will support only TypeScript 2.1, so we no longer provide backwards compatibility to TS 1.8.
Alex Rickabaugh
Alex Eagle
Rob Wormald