When targeting x64, MinGW-w64 complains about conversions between
32-bit long and 64-bit pointers. Fix this by reusing the
GNUTLS_POINTER_TO_SOCKET_CAST / GNUTLS_SOCKET_TO_POINTER_CAST logic
from gtls.c, moving it to warnless.h as CURLX_POINTER_TO_INTEGER_CAST /
CURLX_INTEGER_TO_POINTER_CAST.

Closes https://github.com/curl/curl/pull/2341

Update clang to version 3.9 and GCC to version 6.

Closes https://github.com/curl/curl/pull/2345

Fixes #2342

- Add OpenSSL 1.1.1 to the header/library version lists.

- Detect OpenSSL 1.1.1 library using its function ERR_clear_last_mark,
  which was added in that version.

Prior to this change an erroneous header/library mismatch was caused by
lack of OpenSSL 1.1.1 detection. I tested using openssl-1.1.1-pre1.

Closes https://github.com/curl/curl/pull/2335

Detected using the `codespell` tool.

Also contains one URL protocol upgrade.

Closes https://github.com/curl/curl/pull/2334

Reported-by: Stefan Kanthak and Rod Widdowson

Fixes #2325

- Add macros to the top of the makefile for rc and mt utilities so that
  it is easier to change their locations.

Bug: https://curl.haxx.se/mail/lib-2018-02/0075.html
Reported-by: Stefan Kanthak

Closes https://github.com/curl/curl/issues/2329

Co-authored-by: Stefan Kanthak

Closes https://github.com/curl/curl/issues/2330
Closes https://github.com/curl/curl/pull/2331

- Add new option CURLOPT_RESOLVER_START_FUNCTION to set a callback that
  will be called every time before a new resolve request is started
  (ie before a host is resolved) with a pointer to backend-specific
  resolver data. Currently this is only useful for ares.

- Add new option CURLOPT_RESOLVER_START_DATA to set a user pointer to
  pass to the resolver start callback.

Closes https://github.com/curl/curl/pull/2311

- In keeping with the naming of our other connect timeout options rename
  CURLOPT_HAPPY_EYEBALLS_TIMEOUT to CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.

This change adds the _MS suffix since the option expects milliseconds.
This is more intuitive for our users since other connect timeout options
that expect milliseconds use _MS such as CURLOPT_TIMEOUT_MS,
CURLOPT_CONNECTTIMEOUT_MS, CURLOPT_ACCEPTTIMEOUT_MS.

The tool option already uses an -ms suffix, --happy-eyeballs-timeout-ms.

Follow-up to 2427d94c which added the lib and tool option yesterday.

Ref: https://github.com/curl/curl/pull/2260

SASL PLAIN is a standard, LOGIN only a draft. The LOGIN draft says
PLAIN should be used instead if available.

- Add new option CURLOPT_HAPPY_EYEBALLS_TIMEOUT to set libcurl's happy
  eyeball timeout value.

- Add new optval macro CURL_HET_DEFAULT to represent the default happy
  eyeballs timeout value (currently 200 ms).

- Add new tool option --happy-eyeballs-timeout-ms to expose
  CURLOPT_HAPPY_EYEBALLS_TIMEOUT. The -ms suffix is used because the
  other -timeout options in the tool expect seconds not milliseconds.

Closes https://github.com/curl/curl/pull/2260

Follow-up to 50d1b337.

Caught by AppVeyor.

This enables users to preresolve but still take advantage of happy
eyeballs and trying multiple addresses if some are not connecting.

Ref: https://github.com/curl/curl/pull/2260

URL: https://curl.haxx.se/mail/lib-2018-02/0072.html

... not of the #define was set at build-time!

removed SSLKEYLOGFILE support (fixed)

removed "consider SSL patches" (outdated)

Closes #2310

Reported-by: Guido Berhoerster
Fixes #2314
Closes #2316

Previously, it would only check for max length if the existing alloc
buffer was to small to fit it, which often would make the header still
get used.

Reported-by: Guido Berhoerster
Bug: https://curl.haxx.se/mail/lib-2018-02/0056.html

Closes #2315

Reported-by: Erik Johansson
Bug: https://github.com/curl/curl/commit/d9392268131c1b8d18dec3fa30e0bded833a5db7#commitcomment-27607495

Also expanded the CURL_REFUSE_CLEARTEXT section with more ideas.

The list of state names (used in debug builds) was out of sync in
relation to the list of states (used in all builds).

I now added an assert to make sure the sizes of the two lists match, to
aid in detecting this mistake better in the future.

Regression since c92d2e14, shipped in 7.58.0.

Reported-by: Somnath Kundu

Fixes #2312
Closes #2313

This reverts commit de9fac00.

Reported-by: Jay Satiro

Follow-up to b46cfbc0.

Caught by Travis CI.

... to verify it builds and works fine.

Ref: https://curl.haxx.se/mail/lib-2017-09/0031.html

Closes #1872

Closes #1603

Closes #1254