feat(dart/transform) Register parameter metadata information

Adds any metadata attached to a parameter to the "parameters" value
passed in to `registerType`.

For example:
`MyComponent(@Inject(Foo) foo)` generates
`"parameters": const [const [const Inject(Foo)]]`

Also reorganizes the testing code.

Closes #7

modules/angular2/src/transform/common/formatter.dart

@@ -4,7 +4,7 @@ import 'package:dart_style/dart_style.dart';
 
 import 'logging.dart';
 
-DartFormatter _formatter;
+DartFormatter _formatter = null;
 
 void init(DartFormatter formatter) {
   if (_formatter != null) {