Storsjo pointed out how setting CURLOPT_NOBODY to 0 could be downright
  confusing as it set the method to either GET or HEAD. The example he showed
  looked like:

   curl_easy_setopt(curl, CURLOPT_PUT, 1);
   curl_easy_setopt(curl, CURLOPT_NOBODY, 0);

  The new way doesn't alter the method until the request is about to start. If
  CURLOPT_NOBODY is then 1 the HTTP request will be HEAD. If CURLOPT_NOBODY is
  0 and the request happens to have been set to HEAD, it will then instead be
  set to GET. I believe this will be less surprising to users, and hopefully
  not hit any existing users badly.

  whenever you attempt to open a new connection.

  (http://curl.haxx.se/docs/adv_20090303.html also known as CVE-2009-0037) in
  which previous libcurl versions (by design) can be tricked to access an
  arbitrary local/different file instead of a remote one when
  CURLOPT_FOLLOWLOCATION is enabled. This flaw is now fixed in this release
  together this the addition of two new setopt options for controlling this
  new behavior:

  o CURLOPT_REDIR_PROTOCOLS controls what protocols libcurl is allowed to
  follow to when CURLOPT_FOLLOWLOCATION is enabled. By default, this option
  excludes the FILE and SCP protocols and thus you nee to explicitly allow
  them in your app if you really want that behavior.

  o CURLOPT_PROTOCOLS controls what protocol(s) libcurl is allowed to fetch
  using the primary URL option. This is useful if you want to allow a user or
  other outsiders control what URL to pass to libcurl and yet not allow all
  protocols libcurl may have been built to support.

  plain FTP connections, and it will then allow MKD to fail once and retry the
  CWD afterwards. This is especially useful if you're doing many simultanoes
  connections against the same server and they all have this option enabled,
  as then CWD may first fail but then another connection does MKD before this
  connection and thus MKD fails but trying CWD works! The numbers can
  (should?) now be set with the convenience enums now called
  CURLFTP_CREATE_DIR and CURLFTP_CREATE_DIR_RETRY.

  Tests has proven that if you're making an application that uploads a set of
  files to an ftp server, you will get a noticable gain in speed if you're
  using multiple connections and this option will be then be very useful.

functions are.

  interface and setting CURLMOPT_MAXCONNECTS to something less than the number
  of handles you add to the multi handle. All the connections that didn't fit
  in the cache would not be properly disconnected nor freed!

  version 1.1 instead of 1.0 like before. This change also introduces the new
  proxy type for libcurl called 'CURLPROXY_HTTP_1_0' that then allows apps to
  switch (back) to CONNECT 1.0 requests. The curl tool also got a --proxy1.0
  option that works exactly like --proxy but sets CURLPROXY_HTTP_1_0.

  I updated all test cases cases that use CONNECT and I tried to do some using
  --proxy1.0 and some updated to do CONNECT 1.1 to get both versions run.

  CURLOPT_SOCKS5_GSSAPI_SERVICE and CURLOPT_SOCKS5_GSSAPI_NEC to allow libcurl
  to do GSS-style authentication with SOCKS5 proxies. The curl tool got the
  options called --socks5-gssapi-service and --socks5-gssapi-nec to enable
  these.

  to set desired block size to use for TFTP transfers instead of the default
  512 bytes.

  They basically offer the same thing the NO_PROXY environment variable only
  offered previously: list a set of host names that shall not use the proxy
  even if one is specified.

clarity.  This does fix one problem that causes ;type=i FTP URLs
to fail in the Turkish locale when CURLOPT_PROXY_TRANSFER_MODE is
used (test case 561)

Added tests 561 and 1092 through 1094 to test various combinations
of ;type= and ;mode= URLs that could potentially fail in the Turkish
locale.

curl_easy_reset() by creating Curl_init_userdefined(). This had the side effect
of fixing curl_easy_reset() so it now also resets CURLOPT_FTP_FILEMETHOD and
CURLOPT_SSL_SESSIONID_CACHE

  (http://curl.haxx.se/bug/view.cgi?id=2413067) that identified a problem that
  would cause libcurl to mark a DNS cache entry "in use" eternally if the
  subsequence TCP connect failed. It would thus never get pruned and refreshed
  as it should've been.

  now has an improved ability to do right when the multi interface (both
  "regular" and multi_socket) is used for SCP and SFTP transfers. This should
  result in (much) less busy-loop situations and thus less CPU usage with no
  speed loss.

specified data pointer was head.

in the parse_remote_port() function as the scope id has already been stripped
from the string.

  addresses if they were very long (>39 letters) due to a too strict address
  validity parser. It now accepts addresses up to 45 bytes long.

  there are servers "out there" that relies on the client doing this broken
  Digest authentication. Apache even comes with an option to work with such
  broken clients.

  The difference is only for URLs that contain a query-part (a '?'-letter and
  text to the right of it).

  libcurl now supports this quirk, and you enable it by setting the
  CURLAUTH_DIGEST_IE bit in the bitmask you pass to the CURLOPT_HTTPAUTH or
  CURLOPT_PROXYAUTH options. They are thus individually controlled to server
  and proxy.

  (http://curl.haxx.se/bug/view.cgi?id=2351645) that identified a problem with
  the multi interface that occured if you removed an easy handle while in
  progress and the handle was used in a HTTP pipeline.

  when uploading files to a single FTP server using multiple easy handle
  handles with the multi interface. Occasionally a handle would stall in
  mysterious ways.

  The problem turned out to be a side-effect of the ConnectionExists()
  function's eagerness to re-use a handle for HTTP pipelining so it would
  select it even if already being in use, due to an inadequate check for its
  chances of being used for pipelnining.

  problem with my CURLINFO_PRIMARY_IP fix from October 7th that caused a NULL
  pointer read. I also took the opportunity to clean up this logic (storing of
  the connection's IP address) somewhat as we had it stored in two different
  places and ways previously and they are now unified.

inclusion by the curl tool without colliding with the curl_strequal functions.

Changed checkprefix() to use it and those instances of strnequal() that
compare host names or other protocol strings that are defined to be
independent of case in the C locale.  This should fix a few more
Turkish locale problems.

by coverity.com

--disable-proxy mode.
Removed some unnecessary prototypes.

CURLOPT_PROXYUSERPWD

  make CURLOPT_PROXYUSERPWD sort of deprecated. The primary motive for adding
  these new options is that they have no problems with the colon separator
  that the CURLOPT_PROXYUSERPWD option does.

used in strequal.c so now all test cases run fine for me again.

  (http://curl.haxx.se/bug/view.cgi?id=2154627) which pointed out that libcurl
  uses strcasecmp() in multiple places where it causes failures when the
  Turkish locale is used. This is because 'i' and 'I' isn't the same letter so
  strcasecmp() on those letters are different in Turkish than in English (or
  just about all other languages). I thus introduced a totally new internal
  function in libcurl (called Curl_ascii_equal) for doing case insentive
  comparisons for english-(ascii?) style strings that thus will make "file"
  and "FILE" match even if the Turkish locale is selected.

_ Update RPG binding accordingly.
_ Fix new options comments.