Avoid 'interface' literal that some MinGW versions define as a macro

Do not try to resolve interfaces names via DNS by recognizing interface
names in a few ways.  If the interface option argument has a prefix of
"if!" then treat the argument as only an interface.  Similarly, if the
interface argument is the name of an interface (even if it does not have
an IP address assigned), treat it as an interface name.  Finally, if the
interface argument is prefixed by "host!" treat it as a hostname that
must be resolved by /etc/hosts or DNS.

These changes allow a client using the multi interfaces to avoid
blocking on name resolution if the interface loses its IP address or
disappears.

5 more bugfixes, 5 more contributors

Fixed the connection reuse detection in ConnectionExists() when
comparing a new connection that is non-SSL based against that of a SSL
based connection that has become so by being upgraded via TLS.

This is a regression since who knows when. When spotting that a HTTP
proxy is used we must not uncondititionally enable the HTTP protocol
since if we do tunneling through the proxy we're still using the target
protocol.

Reported by: Naveen Chandran

As a follow-up from commit d5b5f64b, clear the sock_accepted status
when such a socket is closed to avoid a re-used connection to retain the
state wrongly.

Bug: http://curl.haxx.se/mail/lib-2011-12/0079.html

Starting with some recent OpenSSL versions (1.0.0e was mentioned)
linking with a static openssl requires a set of more libs to be linked
on Windows.

Thanks also to Steve Holme and Martin Storsjö for additional feedback.

Bug: http://curl.haxx.se/mail/lib-2011-12/0063.html
Reported by: Ward Willats

This improves portability of the examples.  This patch was
submitted to the OpenBSD ports collection by naddy.

This is a left-over fix from commit b7e242de that Tom Wright
suggested.

Reported by: Ward Willats

If no SSLv2 was detected in OpenSSL by configure, then we enforce the
OPENSSL_NO_SSL2 define as it seems some people report it not being
defined properly in the OpenSSL headers.

If the option is set to 0, the default timeout will be used - which in
modern libcurl versions equals 300 seconds (== 5 minutes).

Bug: http://curl.haxx.se/mail/lib-2011-12/0051.html
Reported by: Vladimir Grishchenko

Adds a timer based off of CURLINFO_TOTAL_TIME that is used to perform
certain actions after a minimum amount of time has passed using the
progress function. As a consequence the curl handle is now also passed
into the progress function. Progress example now also includes an
example of how to retreive the TOTAL_TIME and print it out.

8 more bugs, 5 more contributors

When a 32 digit hex key is given as a hostkey md5 checksum, the code
would still run it against the knownhost check and not properly
acknowledge that the md5 should then be the sole guide for.

The verbose output now includes the evaluated MD5 hostkey checksum.

Some related source code comments were also updated.

Bug: http://curl.haxx.se/bug/view.cgi?id=3451592
Reported by: Reza Arbab

As there are different return codes for host vs proxy errors, this function
now properly returns the code properly depending on what was attempted to get
resolved.

Bug: http://curl.haxx.se/mail/archive-2011-12/0010.html
Reported by: Jason Liu

When making a distinction which return code to return, the code previously
only regarded HTTP proxies to be proxies and thus return host-related errors
for failures on other proxy types than HTTP. Now all proxy types will be
considered proxies...

Keep track of which sockets that are the result of accept() calls and
refuse to call the closesocket callback for those sockets. Test case 596
now verifies that the open socket callback is called the same number of
times as the closed socket callback for active FTP connections.

Bug: http://curl.haxx.se/mail/lib-2011-12/0018.html
Reported by: Gokhan Sengun

When the new socket is created for an active connection, it is now done
using the open socket callback.

Test case 596 was modified to run fine, although it hides the fact that
the close callback is still called too many times, as it also gets
called for closing sockets that were created with accept().

Moved out into a separate function to work as a "generic" socket()
replacement.

test 595: for passive FTP
test 596: for active FTP

Ensure that CURLE_OK is returned if setting the name servers is successfull.

If the socket callback function pointer hasn't been set, we must not
attempt to use it. Commit adc88ca2 made it more likely to occur.

If the first name server is not available, the multi interface does
not invoke the socket_cb when the DNS request to the first name server
timesout.  Ensure that the list of sockets are always updated after
calling Curl_resolver_is_resolved.

This bug can be reproduced if Curl is complied with --enable_ares and
your code uses the multi socket interfaces and the
CURLMOPT_SOCKETFUNCTION option.  To test try:
  iptables -I INPUT \
           -s $(sed -n -e '/name/{s/.* //p;q}' /etc/resolv.conf)/32 \
           -j REJECT
and then run a program which uses the multi-interface.

Changed the eob detection to work across the whole of the buffer so that
lines that begin with a dot (which the server will have escaped) are
passed to the client application correctly.

Using libtool 1.5.x (x < 26) with autoconf 2.6x or later generates warnings
due to some libtool variables not following naming convention for variables
that will be cached.

This is addressed renaming a couple of variables to make these follow expected
naming convention.

5 bugfixes and 1 new contributor

libidn option adjusted in order to use pkg-config info when available
in a similar way as we already do for other libraries.

By making sure the function can detect an "end of body" sequence
immediately on the first line, test 811 is now enabled.

Previously the log function would just filter out all CR and LF
occurances from the log to make it more readable. This had the downside
that it made it very hard to see CR LFs when they actually matters.

Now, they're instead converted to "[CR]" and "[LR]" in the log to become
apparent to readers.

Curl_pop3_write() now has a state machine that scans for the end of a
POP3 body so that the CR LF '.' CR LF sequence can come in everything
from one up to five subsequent packets.

Test case 810 is modified to use SLOWDOWN which makes the server pause
between each single byte and thus makes the POP3 body get sent to curl
basically one byte at a time.