feat(dart/transform) Remove import of dart:mirrors

+ Precede the call to `new ReflectionCapabilities()` with our generated
code which populates the reflection map statically.
+ Add the import of our generated code.
+ Once we are generating all necessary code, we will remove the
import of reflection_capabilities.dart and the instantiation of
`ReflectionCapabilities`, cutting the dependency on dart:mirrors.

Closes #761

modules/angular2/test/transform/two_deps_files/expected/index.bootstrap.dart

@@ -1,10 +1,11 @@
+library angular2.src.transform.generated;
+
 import 'package:angular2/src/reflection/reflection.dart' show reflector;
 import 'bar.dart' as i0;
 import 'foo.dart' as i1;
 import 'package:angular2/src/core/annotations/annotations.dart' as i2;
-import 'index.dart' as i3;
 
-main() {
+setupReflection() {
   reflector
     ..registerType(i0.MyComponent, {
       "factory":
@@ -12,5 +13,4 @@ main() {
       "parameters": const [const [i1.MyContext, String]],
       "annotations": const [const i2.Component(selector: i1.preDefinedSelector)]
     });
-  i3.main();
 }

modules/angular2/test/transform/two_deps_files/index.dart

@@ -1,8 +1,10 @@
 library web_foo;
 
 import 'package:angular2/src/core/application.dart';
+import 'package:angular2/src/reflection/reflection_capabilities.dart';
 import 'bar.dart';
 
 void main() {
+  reflector.reflectionCapabilities = new ReflectionCapabilities();
   bootstrap(MyComponent);
 }