- Save a parallel transfer's result code only when it fails and the
  transfer is not being retried.

Prior to this change the result code was always set which meant that a
failed result could be erroneously discarded if a different transfer
later had a successful result (CURLE_OK).

Before:

> curl --fail -Z https://httpbin.org/status/404 https://httpbin.org/delay/10
> echo %ERRORLEVEL%
0

After:

> curl --fail -Z https://httpbin.org/status/404 https://httpbin.org/delay/10
> echo %ERRORLEVEL%
22

Closes #xxxx

Closes #6727

The --create-file-mode code logic accepted the value but never actually
passed it on to libcurl!

Follow-up to a7696c73436f (shipped in 7.75.0)
Reported-by: Johannes Lesr
Fixes #6657
Closes #6666

Follow-up to 09363500b
Reported-by: Emil Engler
Reviewed-by: Daniel Gustafsson
Closes #6668

Previously only a single -b cookie parameter was supported with the last
one winning.  This adds support for supplying multiple -b params to have
them serialized semicolon separated.  Both cookiefiles and cookies can be
entered multiple times.

Closes #6649
Reviewed-by: Daniel Stenberg <daniel@haxx.se>

- New libcurl options CURLOPT_DOH_SSL_VERIFYHOST,
  CURLOPT_DOH_SSL_VERIFYPEER and CURLOPT_DOH_SSL_VERIFYSTATUS do the
  same as their respective counterparts.

- New curl tool options --doh-insecure and --doh-cert-status do the same
  as their respective counterparts.

Prior to this change DOH SSL certificate verification settings for
verifyhost and verifypeer were supposed to be inherited respectively
from CURLOPT_SSL_VERIFYHOST and CURLOPT_SSL_VERIFYPEER, but due to a bug
were not. As a result DOH verification remained at the default, ie
enabled, and it was not possible to disable. This commit changes
behavior so that the DOH verification settings are independent and not
inherited.

Ref: https://github.com/curl/curl/pull/4579#issuecomment-554723676

Fixes https://github.com/curl/curl/issues/4578
Closes https://github.com/curl/curl/pull/6597

Prevent both --fail and --fail-with-body on the same command line.

Verify with test 349, 360 and 361.

Closes #6449

- Deduplicate the logic used by write-out and write-out json.

Rather than have separate writeLong, writeString, etc, logic for
each of write-out and write-out json instead have respective shared
functions that can output either format and a 'use_json' parameter to
indicate whether it is json that is output.

This will make it easier to maintain. Rather than have to go through
two sets of logic now we only have to go through one.

- Support write-out %{errormsg} and %{exitcode} in json.

- Clarify in the doc that %{exitcode} is the exit code of the transfer.

Prior to this change it just said "The numerical exitcode" which
implies it's the exit code of the tool, and it's not necessarily that.

Closes https://github.com/curl/curl/pull/6544

- Add support services without region and service prefixes in
the URL endpoint (ex. Min.IO, GCP, Yandex Cloud, Mail.Ru Cloud Solutions, etc)
by providing region and service parameters via aws-sigv4 option.
- Add [:region[:service]] suffix to aws-sigv4 option;
- Fix memory allocation errors.
- Refactor memory management.
- Use Curl_http_method instead() STRING_CUSTOMREQUEST.
- Refactor canonical headers generating.
- Remove repeated sha256_to_hex() usage.
- Add some docs fixes.
- Add some codestyle fixes.
- Add overloaded strndup() for debug - curl_dbg_strndup().
- Update tests.

Closes #6524