title: docker api, attaching container returns extra characters
body: <p>I'm consuming docker api from javascript in the browser,
  I start one container that executes 'composer install' command then I attach to it to get the output.
  Everything works but I get some extra characters at the beginning of each line</p>
  
  <pre><code>    -Installing assets using the hard copy option
      PInstalling assets for Symfony\Bundle\FrameworkBundle into web/bundles/framework
      BInstalling assets for Propel\PropelBundle into web/bundles/propel
  </code></pre>
  
  <p>P and B before installing word in this two line example in particular, but in reality are random letters or numbers.</p>
  
  <p>do I need to parse or process the output of attached container before displaying it ? </p>
  
  <p>Note: Not only from browser but from terminal curl command too, also getting same random characters at beginning of almost line</p>
  
  <pre><code>curl 'http://localhost/dockerapi/containers/54053a10dc05b45c400b16733d2edd1cbfb6b6d877badf5cc26d3da7d2165375/attach?logs=1&amp;stream=1&amp;stdout=1' 
  -X POST 
  -H 'Origin: http://localhost' 
  -H 'Accept-Encoding: gzip,deflate,sdch' 
  -H 'Accept-Language: en-US,en;q=0.8,es;q=0.6' 
  -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36'
  -H 'Accept: application/json, text/plain, */*' 
  -H 'Referer: http://localhost/' 
  -H 'Connection: keep-alive'
  -H 'Content-Length: 0' 
  --compressed
  </code></pre>