title: CORS - ...does not support http method 'OPTIONS'
body: <p>When CORS is configured (and seemingly working) it still returns a 405 for the OPTIONS verb.</p>
  
  <p>CORS is configured via the Owin NuGet package, <code>Microsoft.Owin.Cors</code> and it seems to return the correct headers.</p>
  
  <p>I notice the issue in Fiddler when I fake a preflight OPTIONS request. The headers come back properly when I propose that I am calling from an allowed domain and they are correctly absent if I propose some other domain - its working.</p>
  
  <p>But why the 405?</p>
  
  <p><code>
  HTTP/1.1 405 Method Not Allowed
  Cache-Control: no-cache
  Pragma: no-cache
  Allow: GET,PUT,DELETE
  Content-Type: application/xml; charset=utf-8
  Expires: -1
  Server: Microsoft-IIS/8.0
  Access-Control-Allow-Origin: <a href="http://localhost:12345" rel="nofollow">http://localhost:12345</a>
  X-AspNet-Version: 4.0.30319
  X-Powered-By: ASP.NET
  Date: Thu, 01 Oct 2015 18:59:32 GMT
  Content-Length: 96</p>
  
  <p><code>&lt;Error&gt;&lt;Message&gt;The requested resource does not support http method 'OPTIONS'.&lt;/Message&gt;&lt;/Error&gt;</code>
  </code></p>
  
  <p>Note the <code>Access-Control-Allow-Origin</code> is present, so I guess the browser will be okay, or will the browser be 'put off' by the negative 405?</p>