Reconsider the redirection code in the request module.

[charbugs]

Comment of resolveRedirect():
/**

• XMLHttpRequest actually follows the redirects by its own. But doing this
• with a POST request will end in a GET request, at least on
• Chromium 53.0.2785.89 Built on 8.5.
• So we resolve the redirects with a HEAD request.
  */