Added CURL_VERSION_ASYNCHDNS

and I don't think we need it.

   CURLOPT_SSL_CTX_FUNCTION to set a callback that gets called with the
   OpenSSL's ssl_ctx pointer passed in and allow a callback to act on it. If
   anything but CURLE_OK is returned, that will also be returned by libcurl
   all the way back. If this function changes the CURLOPT_URL, libcurl will
   detect this and instead go use the new URL.

   CURLOPT_SSL_CTX_DATA is a pointer you set to get passed to the callback set
   with CURLOPT_SSL_CTX_FUNCTION.

a "plain" Negotiate as well.

to add more method in the future.

added.

known to really NEED it as another system that doesn't have it came up:
very old Linux libc5-based systems (as addition to all HPUX versions).

The only known system at this point is AIX.

defines in the public external header files

make an adjustment to catch this.

disables the host name check in the FOLLOWLOCATION code. With that option
set, libcurl will send user+password to all hosts.

AIX when this fix is applied and I cannot see how this will break any
systems.

the design draft mentioned and what I think is fit