title: eclipse update sites: HTTP Proxy Authentication Required error
body: <p>when I go to Install new software and select an update site, I get a "HTTP Proxy Authentication Required" error. </p>
  
  <p>I have searched the internets for quite some time, and I still did not get an answer.</p>
  
  <p>Facts:</p>
  
  <ul>
  <li>I get this error for every update site.</li>
  <li>I am able to access the update site link both in an internal or external browser.</li>
  <li>I am using the "native" proxy in eclipse network settings.</li>
  <li>direct proxy in eclipse network settings does not work either.</li>
  <li>our helpdesk told me that it's not possible to set up the manual proxy in eclipse network settings (or they don't know)</li>
  <li>I've tried manually inserting a proxy server:port that I found in a proxy.pac file that I've discovered, no luck...</li>
  <li>I've tried reinstalling Eclipse, re-adding and/or reloading repositories and deleting repo cache dir</li>
  <li>I'm using: -Djava.net.preferIPv4Stack=true in ini file</li>
  <li>I've tried mirroring the repositories using both methods, but log file gives the same proxy error</li>
  </ul>
  
  <p>My system:
  Eclipse for PHP Developers<br>
  Version: Luna Service Release 1a (4.4.1)<br>
  Build id: 20150109-0600<br>
  Windows 7, 64bit<br></p>