refactor(dart/transform): Remove ngData

Now that we have `Parser`, `ngData` is redundant & unnecessary.

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

@@ -1,35 +0,0 @@
-library angular2.transform.common.ng_data;
-
-import 'dart:convert';
-
-const NG_DATA_VERSION = 1;
-
-class NgData extends Object {
-  int importOffset = 0;
-  int registerOffset = 0;
-  List<String> imports = [];
-
-  NgData();
-
-  factory NgData.fromJson(String json) {
-    var data = JSON.decode(json);
-    return new NgData()
-      ..importOffset = data['importOffset']
-      ..registerOffset = data['registerOffset']
-      ..imports = data['imports'];
-  }
-
-  String toJson() {
-    return JSON.encode({
-      'version': NG_DATA_VERSION,
-      'importOffset': importOffset,
-      'registerOffset': registerOffset,
-      'imports': imports
-    });
-  }
-
-  @override
-  String toString() {
-    return '[NgData: ${toJson()}]';
-  }
-}