title: tsc not excluding node_modules
body: <pre><code>{
    "compilerOptions": {
      "target": "es5",
      "module": "commonjs",
      "moduleResolution": "node",
      "sourceMap": true,
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "removeComments": false,
      "noImplicitAny": false
    },
    "exclude": [
      "node_modules",
      "typings/main",
      "typings/main.d.ts"
    ]
  }
  </code></pre>
  
  <p>I'm trying to upgrade an angular2/beta8 app to RC1, and I'm doing so by basically restructuring according to the Quickstart guide.</p>
  
  <p>I copied its tsconfig.json into my project directory. I think I've got everything else ready,but when I run <code>tsc</code>, I get all kinds of errors within files in my node_modules folder. Why is it even looking in there in the first place? </p>