fix(bundles): remove polyfills from angular2.js bundle

BREAKING CHANGE:

Previously `angular2.js`, `angular2.min.js` and `angular2.dev.js` bundles
would have zone.js and reflect-metadata pre-appended. New bundles don't
contain zone.js nor reflect-metadata - those external dependencies can
be easily loaded into a browser using `angular2-polyfills.js`

Closes #5881

gulpfile.js

@@ -1165,7 +1165,7 @@ gulp.task('bundles.js.umd.min', ['!bundles.js.umd', '!bundle.ng.polyfills'], fun
 gulp.task('!bundle.js.prod.deps', ['!bundle.js.prod'], function() {
   var bundler = require('./tools/build/bundle');
 
-  return merge2(addDevDependencies('angular2.js'),
+  return merge2(bundler.modify(['dist/build/angular2.js'], 'angular2.js'),
                 bundler.modify(['dist/build/http.js'], 'http.js'),
                 bundler.modify(['dist/build/router.js'], 'router.js'),
                 bundler.modify(['dist/build/upgrade.js'], 'upgrade.js'))
@@ -1176,7 +1176,7 @@ gulp.task('!bundle.js.min.deps', ['!bundle.js.min'], function() {
   var bundler = require('./tools/build/bundle');
   var uglify = require('gulp-uglify');
 
-  return merge2(addDevDependencies('angular2.min.js'),
+  return merge2(bundler.modify(['dist/build/angular2.min.js'], 'angular2.min.js'),
                 bundler.modify(['dist/build/http.min.js'], 'http.min.js'),
                 bundler.modify(['dist/build/router.min.js'], 'router.min.js'),
                 bundler.modify(['dist/build/upgrade.min.js'], 'upgrade.min.js'))
@@ -1220,16 +1220,18 @@ function addDevDependencies(outputFile) {
 gulp.task('!bundle.js.dev.deps', ['!bundle.js.dev'], function() {
   var bundler = require('./tools/build/bundle');
 
-  return merge2(addDevDependencies('angular2.dev.js'),
+  return merge2(bundler.modify(['dist/build/angular2.dev.js'], 'angular2.dev.js'),
                 bundler.modify(['dist/build/http.dev.js'], 'http.dev.js'),
                 bundler.modify(['dist/build/router.dev.js'], 'router.dev.js'),
                 bundler.modify(['dist/build/upgrade.dev.js'], 'upgrade.dev.js'))
       .pipe(gulp.dest('dist/js/bundle'));
 });
 
 gulp.task('!bundle.web_worker.js.dev.deps', ['!bundle.web_worker.js.dev'], function() {
-  return merge2(
-      addDevDependencies("web_worker/ui.dev.js", addDevDependencies("web_worker/worker.dev.js")));
+  var bundler = require('./tools/build/bundle');
+  return merge2(bundler.modify(['dist/build/web_worker/ui.dev.js'], "web_worker/ui.dev.js"),
+                bundler.modify(['dist/build/web_worker/worker.dev.js'], "web_worker/worker.dev.js"))
+      .pipe(gulp.dest('dist/js/bundle'));
 });
 
 gulp.task('!bundle.copy', function() {

tools/broccoli/html-replace/SCRIPTS.html

@@ -16,6 +16,7 @@
     }
   });
 </script>
+<script src="/bundle/angular2-polyfills.js"></script>
 <script src="/bundle/angular2.dev.js"></script>
 <script src="/bundle/http.js"></script>
 <script src="/bundle/router.dev.js"></script>

tools/broccoli/html-replace/SCRIPTS_benchmarks.html

@@ -17,6 +17,7 @@
     }
   });
 </script>
+<script src="/bundle/angular2-polyfills.js"></script>
 <script src="/bundle/angular2.dev.js"></script>
 <script>
   var filename = '@@PATH/@@FILENAME';