Version 1.3.4: released 2009-01-18; changes from 1.3.3

  * Overloaded Network.Curl operations over response representation
    of payloads and headers. Controlled via CurlBuffer and CurlHeader
    classes. New actions:
       - curlGetString_, curlGetResponse_, 
         perform_with_response_, do_curl_, curlHead_
        
  * Provided ByteString instances (strict and lazy)
  * No modification in calling interface to existing exports,
    so backwards compatible.
  * Added Show instance for Network.Curl.Opts.CurlOption
  * curl_version_string, curl_version_number now gives you access
    to version info of underlying lib you _compiled_ the package with.
  * Sync'ed wrt libcurl-7.19.2, so bunch of new options added to
    Network.Curl.Opts. Use version functions to determine if they
    are supported though.
