- 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removed "consider SSL patches" (outdated)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

... so that the memory allocated by applications using libcurl does not
grow per each TLS connection.

Bug: https://bugzilla.redhat.com/1510247

Closes #2297

Closes #2302

Reported-by: Klaus Stein

... just to make it more apparent. Even if it repeats
some pieces of information.

Mentioned-By: Rich Moore

To make more accessible.

Merged in some new language from "URLs are dangerous things" as discussed on
the mailing list a few days ago:

Bug: https://curl.haxx.se/mail/lib-2018-02/0013.html

Test 319 checks proper raw mode data with non-chunked gzip
transfer-encoded server data.
Test 326 checks raw mode with chunked server data.

Bug: #2303
Closes #2308

Bug: https://bugzilla.redhat.com/1542256

Closes #2306

RFC 5321 4.1.1.4 specifies the CRLF terminating the DATA command
should be taken into account when chasing the <CRLF>.<CRLF> end marker.
Thus a leading dot character in data is also subject to escaping.

Tests 911 and test server are adapted to this situation.
New tests 951 and 952 check proper handling of initial dot in data.

Closes #2304

support for SHA-2 was introduced in OpenSSL 0.9.8

Closes #2305