refactor(dart/transform): Remove deprecated angular2/bootstrap

BREAKING CHANGE

Remove the deprecated angular2/bootstrap.ts &
angular2/bootstrap_static.ts libraries.

Browser entry points should import angular2/platform/browser which
supplies the `bootstrap` function.

Closes #7650

tools/broccoli/html-replace/SCRIPTS.html

@@ -9,7 +9,6 @@
     // not even be in src/*. Move them!
     'angular2/src/testing/benchmark_util',
     'angular2/src/facade/browser',
-    'angular2/bootstrap',
     'rxjs'
   ];
   if (@@USE_BUNDLES) {

tools/broccoli/html-replace/SCRIPTS_benchmarks.html

@@ -10,7 +10,6 @@
     // not even be in src/*. Move them!
     'angular2/src/testing/benchmark_util',
     'angular2/src/facade/browser',
-    'angular2/bootstrap',
     'rxjs'
   ];
   if (@@USE_BUNDLES) {