feat(dart/transform): Generate ChangeDetector classes

Use the `ProtoViewDto` created by the render `Compiler` to create a
`ChangeDetectorDefinition`.

From there, generate a subclass of `AbstractChangeDetector` for each
`ChangeDetectorDefinition`.

Run some basic unit tests for the dynamic and JIT change detectors on
pre-generated change detectors.

modules/angular2/test/change_detection/generated/simple_watch_classes.ts

@@ -0,0 +1,5 @@
+// Ignore me, needed to support Angular 2 Dart.
+
+export function getFactoryById(id: string) {
+  return null;
+}