CURLE_SSL_PINNEDPUBKEYNOTMATCH and CURLE_SSL_INVALIDCERTSTATUS

- Show how a certificate can be obtained using OpenSSL.

Bug: https://github.com/bagder/curl/pull/430
Reported-by: Daniel Hwang

s => is

Closes #428

It uses 'Note:' as a prefix as opposed to the common 'Warning:' to take
down the tone a bit.

It adds a warning for using -XHEAD on other methods becasue that may
lead to a hanging connection.

Bug: https://github.com/bagder/curl/pull/411
Reported-by: Viktor Szakats

long => double

Closes #409

If the port number in the proxy string ended weirdly or the number is
too large, skip it. Mostly as a means to bail out early if a "bare" IPv6
numerical address is used without enclosing brackets.

Also mention the bracket requirement for IPv6 numerical addresses to the
man page for CURLOPT_PROXY.

Closes #415

Reported-by: Marcel Raad

In some timing-dependnt cases when a 4xx response immediately followed
after a 150 when a STOR was issued, this function would wrongly return
'complete == true' while 'wait_data_conn' was still set.

Closes #405

Reported-by: Patricia Muscalu

Closes #414
Closes #413

leavit => leaveit

closes #412

This reverts commit a60bde79 I have
pushed by mistake.  Apologies for my incompetent use of the git repo!

It causes dynamic linking issues at run-time after an update of NSS.

Bug: https://lists.fedoraproject.org/pipermail/devel/2015-September/214117.html

changed macro name, moved and renamed script to become docs/libcurl/has.pl,
generate code that is checksrc compliant

RFC 7540 section 8.1.2.2 states: "An endpoint MUST NOT generate an
HTTP/2 message containing connection-specific header fields; any message
containing connection-specific header fields MUST be treated as
malformed"

Closes #401

and some general cleaning up

This fixes another run-time check failure because of a narrowing cast on
Visual C++.

Closes #408

- Warn that cookies without a domain are sent to any domain:
CURLOPT_COOKIELIST, CURLOPT_COOKIEFILE, --cookie

- Note that imported Set-Cookie cookies without a domain are no longer
exported:
CURLINFO_COOKIELIST, CURLOPT_COOKIEJAR, --cookie-jar

tool_sdecls.h:139 warning: comma at end of enumerator list

Introduced in commit 59f3f92b this function is only implemented when
CURL_DISABLE_CRYPTO_AUTH is not defined. As such we shouldn't define
the function in the header file either.