ENABLE_IPV6 depends on HAVE_GETADDRINFO or you will get a
Curl_getaddrinfo_ex error. Enable IPv6 by default, disabling it if
struct sockaddr_in6 is not found in netinet/in.h.

Note that HAVE_GETADDRINFO_THREADSAFE is still not set as it needs more
platform checks even though POSIX requires a thread-safe getaddrinfo.

Verified on Arch Linux x86_64 with glibc 2.20-2 and Linux 3.16-rc7.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>

Rather than always outputting an empty manual page for the '-M' option,
generate a full manual page as done by autotools. For simplicity in
CMake, always generate the gzipped page as it will not be used anyway
when zlib is not available.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>

Reported-By: Luan Cestari

Option --pinnedpubkey takes a path to a public key in DER format and
only connect if it matches (currently only implemented with OpenSSL).

Provides CURLOPT_PINNEDPUBLICKEY for curl_easy_setopt().

Extract a public RSA key from a website like so:
openssl s_client -connect google.com:443 2>&1 < /dev/null | \
sed -n '/-----BEGIN/,/-----END/p' | openssl x509 -noout -pubkey \
| openssl rsa -pubin -outform DER > google.com.der

Improves it for low-latency cases (like the communication with
localhost)

For private keys, use the first match from: user-specified key file
(if provided), ~/.ssh/id_rsa, ~/.ssh/id_dsa, ./id_rsa, ./id_dsa

Note that the previous code only looked for id_dsa files. id_rsa is
now generally preferred, as it supports larger key sizes.

For public keys, use the user-specified key file, if provided.
Otherwise, try to extract the public key from the private key file.
This means that passing --pubkey is typically no longer required,
and makes the key-handling behavior more like OpenSSH.

and separate the example URLs with newlines

As we weren't using the correct phonetic description and doing it correctly
involves funny letters that I'm sure will cause problems for people in a text
document so I instead rephrased it and link to a WAV file with a person
actually saying 'curl'.

Reported-By: Dimitar Boevski

Reported-By: Jonathan Cardoso Machado
URL: http://curl.haxx.se/mail/lib-2014-09/0102.html

The former link was turned into a 404 at some point.

Reported-By: Askar Safin

It interprets them as italic indictors unless we backtick the word.

Added support for Kerberos 5 to the email protocols following the recent
additions in 7.38.0.

Removed Kerberos 4 as this has been gone for a while now.

krb4 has been dropped since a while now

Edited format to look better on the web, added a "it is about trust"
section.

Only minor edits to make it generate nice HTML output using markdown, as
this document serves both in source release tarballs as on the web site.

URL: http://curl.haxx.se/docs/sslcerts.html

Reported-By: Frank Gevaerts

... and a minor wording edit

Dennis Clarke from Blastwave.org for ensuring that nightly builds run
smooth on Solaris!