Regression from 46e16406. Extended test 1560 to verify.

Reported-by: tpaukrt on github
Fixes #3218
Closes #3219

on Linux. To make sure the test suite runs with its newly build tool and
doesn't require an external one present.

Bug: #3198
Closes #3200

The overflow has no real world impact.
Just avoid it for "best practice".

Code change suggested by "The Infinnovation Team" and Daniel Stenberg.
Closes #3184

When not actually following the redirect and the target URL is only
stored for later retrieval, curl always accepted "non-supported"
schemes. This was a regression from 46e16406.

Reported-by: Brad King
Fixes #3210
Closes #3215

Commit efc696a2

 renamed persistant.c to persistent.c to
fix the typo in the name, but missed to update the OpenVMS package
files which still looked for the old name.

Closes #3217
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
Reviewed-by: Viktor Szakats <commit@vszakats.net>

To make it easier to understand other people's and remote builds etc.

Closes #3207

As has been outlined in the DEPRECATE.md document, the axTLS code has
been disabled for 6 months and is hereby removed.

Use a better supported TLS library!

Assisted-by: Daniel Gustafsson
Closes #3194

Closes #3197

... using clang

Closes #3190

Curl_verify_certificate() must use the Curl_ prefix since it is globally
available in the lib and otherwise steps outside of our namespace!

Closes #3201

It is unused since commit f7208df7.

Closes #3204

... revert the mistaken change brought in commit 8440616f.

Reported-by: Alessandro Ghedini
Bug: https://curl.haxx.se/mail/lib-2018-10/0118.html

Closes #3198

MesaLink support was added in commit 57348eb9

 but the
backend was never added to the curl_sslbackend enum in curl/curl.h.
This adds the new backend to the enum and updates the relevant docs.

Closes #3195
Reviewed-by: Daniel Stenberg <daniel@haxx.se>

Closes #3191

CVE-2018-16842
Reported-by: Brian Carpenter
Bug: https://curl.haxx.se/docs/CVE-2018-16842.html

Closes #3123

Detected by UndefinedBehaviorSanitizer

Closes #3187

Closes #3182

Closes #3186

CVE-2018-16839
Reported-by: Harry Sintonen
Bug: https://curl.haxx.se/docs/CVE-2018-16839.html

Regression from b46cfbc0 (7.59.0)
CVE-2018-16840
Reported-by: Brian Carpenter (Geeknik Labs)

Bug: https://curl.haxx.se/docs/CVE-2018-16840.html

system.h selects the proper Sun settings when __SUNPRO_C is defined. The
Sun compiler does not define it when compiling C++ files.  I'm adding a
check also on __SUNPRO_CC to allow curl to work properly also when used
in a C++ project on Sun Solaris.

Closes #3181

The version used for Gskit, NSS, GnuTLS, WolfSSL and schannel.

Available in the root, src and lib dirs.

Closes #3163

See: https://curl.haxx.se/mail/lib-2018-10/0107.html

Use an unsigned variable: as the signed operation behavior is undefined,
this change silents clang-tidy about it.

Ref: https://github.com/curl/curl/pull/3163
Reported-By: Daniel Stenberg

If Curl_protocol_connect() returns an error code,
handle the error instead of switching to the next state.

Closes #3170

When failing to set the 1.3 cipher suite, the wrong string pointer would
be used in the error message. Most often saying "(nil)".

Reported-by: Ricky-Tigg on github
Fixes #3178
Closes #3180

... picked straight from the OpenSSL man page:
https://www.openssl.org/docs/manmaster/man3/SSL_CTX_set_ciphersuites.html

Reported-by: Ricky-Tigg on github
Bug: #3178

This is required for gnutls-serv, which enables a few more tests.

Closes https://github.com/curl/curl/pull/2958

Ensure to clear the session object in case the libssh2 initialization
fails.

It could be argued that the libssh2 error function should be called to
get a proper error message in this case. But since the only error path
in libssh2_knownhost_init() is memory a allocation failure it's safest
to avoid since the libssh2 error handling allocates memory.

Closes #3179
Reviewed-by: Daniel Stenberg <daniel@haxx.se>