Even if deprecated, document it so that people will find it as old
scripts may still use it.

The code said "telnet-options" but no documentation ever said so. It
worked fine since the code is fine with a unique match of the first
part.

It has been deprecated and undocumented since commit ad5ead8b (Dec
2003). --ftp-port is the proper long option name.

To make the aliases list reflect reality.

... moved around options so that parsing the code to find all
single-letter options easier.

Bug: https://curl.haxx.se/mail/lib-2016-04/0126.html
Reported-by: Bru Rom

- checks that each option has its own man page present

- checks that each option is mentioned in its corresponding index man
  page

... although it is deprecated.

This also fixes PolarSSL session resume.

Prior to this change the TLS session information wasn't properly
saved and restored for PolarSSL and mbedTLS.

Bug: https://curl.haxx.se/mail/lib-2016-01/0070.html
Reported-by: Thomas Glanzmann

Bug: https://curl.haxx.se/mail/lib-2016-04/0095.html
Reported-by: Moti Avrahami

Fixes #779

OpenSSL 1.1.0-pre seems to return NULL(?) for a whole lot of those
numbers so make sure the function handles this.

Reported-by: Linus Nordberg

Previously, connections were closed immediately before the user had a
chance to extract the socket when the proxy required Negotiate
authentication.

This regression was brought in with the security fix in commit
79b9d5f1

Closes #655

Closes #716

While being debated (in #716) and a violation of RFC 7230 section 5.4,
this test verifies that the existing functionality works as intended. It
strips the dot from the host name and uses the host without dot
throughout the internals.

Regression introduced in 09b5a998

Bug: https://curl.haxx.se/mail/lib-2016-04/0084.html
Reported-by: BoBo

follow-up commit to 3c1e84f5 as it made curl try a little harder

If buffer is allocated, but nothing is received during prereceive
stage, than number of processed bytes must be zero.

Closes #778

Closes #686 for now.

Adding support for IRIs is a mouthful, but is probably interesting at
least for areas and countries where the use of such "URLs" are growing
popularity.

Closes #776

It got too annoying to type =)

The underlying libcurl option used for this feature is
CURLOPT_FTP_CREATE_MISSING_DIRS which has the ability to retry the dir
creation, but it was never set to do that by the command line tool.

Now it does.

Bug: https://curl.haxx.se/mail/archive-2016-04/0021.html
Reported-by: John Wanghui
Help-by: Leif W

Add WITH_MBEDTLS option. Make WITH_SSL, WITH_MBEDTLS and ENABLE_WINSSL
options mutual exclusive.

Closes #606

As of commit d9f3b365