title: hapi.js Cors Pre-flight not returning Access-Control-Allow-Origin header
body: <p>I have an ajax file upload using (Dropzone js). which sends a file to my hapi server. I realised the browser sends a PREFLIGHT OPTIONS METHOD. but my hapi server seems not to send the right response headers so i am getting errors on chrome.
  here is the error i get on chrome</p>
  
  <pre><code>XMLHttpRequest cannot load http://localhost:3000/uploadbookimg. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:4200' is therefore not allowed access.
  </code></pre>
  
  <p>this is the hapi js route handler</p>
  
  <pre><code>server.route({
          path: '/uploadbookimg',
          method: 'POST',
          config: {
              cors : true,
              payload: {
                  output: 'stream',
                  parse: true,
                  allow: 'multipart/form-data'
              },
          handler: require('./books/webbookimgupload'),
          }
      });
  </code></pre>
  
  <p>In my understanding hapi js should send all cors headers from the Pre-fight (OPTIONS) request.
  Cant understand why its is not</p>
  
  <p>Network request /response from chrome</p>
  
  <pre><code>**General**
  Request Method:OPTIONS
  Status Code:200 OK
  Remote Address:127.0.0.1:3000
  
  **Response Headers**
  view parsed
  HTTP/1.1 200 OK
  content-type: application/json; charset=utf-8
  cache-control: no-cache
  vary: accept-encoding
  Date: Wed, 27 Apr 2016 07:25:33 GMT
  Connection: keep-alive
  Transfer-Encoding: chunked
  
  **Request Headers**
  view parsed
  OPTIONS /uploadbookimg HTTP/1.1
  Host: localhost:3000
  Connection: keep-alive
  Pragma: no-cache
  Cache-Control: no-cache
  Access-Control-Request-Method: POST
  Origin: http://localhost:4200
  User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.87 Safari/537.36
  Access-Control-Request-Headers: accept, cache-control, content-type
  Accept: */*
  Referer: http://localhost:4200/books/upload
  Accept-Encoding: gzip, deflate, sdch
  Accept-Language: en-US,en;q=0.8
  </code></pre>
  
  <p>Thanks in advance</p>