Closes #1280

curl.1 is generated by the cmdline-opts script since 4c49b835.

- Change CURLOPT_PROXY_CAPATH to return CURLE_NOT_BUILT_IN if the option
  is not supported, which is the same as what we already do for
  CURLOPT_CAPATH.

- Change the curl tool to handle CURLOPT_PROXY_CAPATH error
  CURLE_NOT_BUILT_IN as a warning instead of as an error, which is the
  same as what we already do for CURLOPT_CAPATH.

- Fix CAPATH docs to show that CURLE_NOT_BUILT_IN is returned when the
  respective CAPATH option is not supported by the SSL library.

Ref: https://github.com/curl/curl/pull/1257

Closes #1264

It isn't easily solved, but with some thinking someone could probably
come up with a working approach?

Closes #1241

Builds with axTLS 2.1.2. This then also breaks compatibility with axTLS
< 2.1.0 (the older API)

... and fix the session_id mixup brought in 04b4ee54

Fixes #1220

- Document in --socks* opts they're still mutually exclusive of --proxy.

Partial revert of 423a93ce; I had misinterpreted the SOCKS proxy +
HTTP/HTTPS proxy combination.

- Document in --socks* opts that --preproxy can be used to specify a
  SOCKS proxy at the same time --proxy is used with an HTTP/HTTPS proxy.

... instead of the OpenSSL mutex page.

Ref: https://sourceforge.net/blog/introducing-https-for-project-websites/
Closes: https://github.com/curl/curl/pull/1247

- Document HTTPS proxy type.

- Document --write-out %{proxy_ssl_verify_result}.

- Document SOCKS proxy + HTTP/HTTPS proxy combination.

HTTPS proxy support was added in 7.52.0 for OpenSSL, GnuTLS and NSS.

Ref: https://github.com/curl/curl/commit/cb4e2be

... refer to the web site for the web versions.

Closes #1231

This bugfix is similar to commit c111178b.

Support is trickling in already.

Closes #1226

The winbuild/ build files is now the single MSVC makefile build choice.

Closes #1215

On Windows it's possible to have input files with CRLF line endings and
a perl that defaults to LF line endings (eg msysgit). Currently that
results in generator output of mixed line endings of CR, LF and CRLF.

This change fixes that issue in the most succinct way by opening the
files in :crlf text mode even when the perl being used does not default
to that mode. (On operating systems that don't have a separate text mode
it's essentially a no-op.) The output continues to be in the perl's
native line ending.

Replace use of fixed macro BUFSIZE to define the size of the receive
buffer.  Reappropriate CURLOPT_BUFFERSIZE to include enlarging receive
buffer size.  Upon setting, resize buffer if larger than the current
default size up to a MAX_BUFSIZE (512KB). This can benefit protocols
like SFTP.

Closes #1222

This has been implemented with commit 9ad034e5.

Implemented since curl-7_36_0-130-g8868a22

Reported-by: Fahim Chandurwala

By supporting this, subsequent connects would load a lot less data from
disk.

Closes #1110

Closes #1211

Closes #1200

Even though it is called --fail-early

Closes #1139