(http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=487567) pointing out that
  libcurl used Content-Range: instead of Range when doing a range request with
  --head (CURLOPT_NOBODY). This is now fixed and test case 1032 was added to
  verify.

is not ANSI C, just a common extension.  This caused problems on
at least Open Watcom C.

enough at detecting compilation errors or at least it has been properly
configured to do so. Configuration heavily depends on this capability, so
if this compiler sanity check fails the configuration process will now fail.

  handshake with a SSLv2 server, and it turned out to be because it didn't
  recognize the cipher named "rc4-md5". In our list that cipher was named
  plainly "rc4". I've now added rc4-md5 to work as an alias as Phil reported
  that it made things work for him again.

  crashed libcurl. This is now addressed by making sure we use "plain send"
  internally when doing the socks handshake instead of the Curl_write()
  function which is designed to use the "target" protocol. That's then SCP or
  SFTP in this case. I also took the opportunity and cleaned up some ssh-
  related #ifdefs in the code for readability.

  libcurl to not tell the app properly when a socket was closed (when the name
  resolve done by c-ares is done) and then immediately re-created and put to
  use again (for the actual connection). Since the closure will make the
  "watch status" get lost in several event-based systems libcurl will need to
  tell the app about this close/re-create case.

  multi interface with pipelining enabled as it would wrongly check for,
  detect and close "dead connections" even though that connection was already
  in use!

number of entries in a provided table is doomed to fail in the long run. Now
we use the NUM_OF_CIPHERS define instead to figure out the amount.

  always fire up a new connection rather than using the existing one when the
  multi interface is used. Original bug report:
  https://bugzilla.redhat.com/show_bug.cgi?id=450140

the check_issuer_cert() proto

warning in the code though but we need NSS' base64.h header for that and we
don't currently have a suitable way to include it as our own base64.h header
kind of "blocks" it.

AC_FOO_IFELSE macros, otherwise temp files are not removed.

Identation adjustment.

is for the TCP connect. I changed it to TIMER_PRETRANSFER which seems to be
what was intended here.

in regard to C standard, third party libraries and operating systems etc.

  libraries are supported. Starting now, each underlying SSL library support
  code does a set of defines for the 16 functions the generic layer (sslgen.c)
  uses (all these new function defines use the prefix "curlssl_"). This
  greatly simplified the generic layer in readability by involving much less
  #ifdefs and other preprocessor stuff and should make it easier for people to
  make libcurl work with new SSL libraries.

  Hopefully I can later on document these 16 functions somewhat as well.

  I also made most of the internal SSL-dependent functions (using Curl_ssl_
  prefix) #defined to nothing when no SSL support is requested - previously
  they would unnecessarily call mostly empty functions.

function(pointer to char,int,int,pointer to void)' is compiler dependent

void *

  functionality killed it due to its unconditional use of
  X509_STORE_set_flags...

  All boolean options (such as -O, -I, -v etc), both short and long versions,
  now always switch on/enable the option named. Using the same option multiple
  times thus make no difference. To switch off one of those options, you need
  to use the long version of the option and type --no-OPTION. Like to disable
  verbose mode you use --no-verbose!

- Added --remote-name-all to curl, which if used changes the default for all
  given URLs to be dealt with as if -O is used. So if you want to disable that
  for a specific URL after --remote-name-all has been used, you muse use -o -
  or --no-remote-name.