title: WebStorm 2016.3 error: Experimental support for decorators is a feature that is subject to change in a future release
body: <p>Hi updated to latest WebStorm and I'm now getting this error:</p>
  
  <pre><code>Error:(52, 14) TS1219:Experimental support for decorators 
  is a feature that is subject to change in a future release. 
  Set the 'experimentalDecorators' option to remove this warning.
  </code></pre>
  
  <p>But in my tsConfig <code>experimentalDecorators</code> are set to true:</p>
  
  <pre><code>{
    "version": "1.5.0",
    "compilerOptions": {
      //...,
      "experimentalDecorators": true,   // &lt;======== HERE
      //...,
    },
    "files": [
      //...
    ],
    "exclude": [ "node_modules" ]
  }
  </code></pre>