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.

Test 815 is disabled for now since libcurl currently doesn't unescape
such lines the way it should. See mail:

http://curl.haxx.se/mail/lib-2011-11/0324.html

configure.ac:1349: error: possibly undefined macro: PKG_CONFIG_LIBDIR

Obviously this is not a problem with pkg-config 0.26 but older versions
seem to show this.

Fix suggested by: Kamil Dudka
Reported by: Guenter
Bug: http://curl.haxx.se/mail/lib-2011-11/0298.html

"Active FTP hangs if server does not open data connection"

The server first sends a 150 and then when libcurl waits for the data
transfer, the server sends a 425.

The protocol parts for these tests do not include QUIT simply because
the error is CURLE_OPERATION_TIMEDOUT (28) which is a generic timeout
error without specificly saying for which connection it concerns, and
for timeouts libcurl marks the control channel as "invalid". As this
test case times out for the data connection it could still use the
control channel.

Added convenience macro to use to check if a handle is using a shared
SSL session, and fixed so that Curl_ssl_close_all() doesn't lock when
the session isn't shared.

Skip a floating point addition operation when integral part of time difference
is zero. This avoids potential floating point addition rounding problems while
preserving decimal part value.

Macros that look like function calls need to be made so that we can use
semicolons properly for indentation and for reducing the risk for
mistakes when using them.

1) enables the Window Size option
2) allows the server to enable the echo mode
3) allows an app using libcurl to disable the default binary mode

Signed-off-by: Laurent Rabret

By setting PROTOPT_NOURLQUERY in the protocol handler struct, the
protocol will get the "query part" of the URL cut off before the data is
handled by the protocol-specific code. This makes libcurl adhere to
RFC3986 section 2.2.

Test 1220 is added to verify a file:// URL with query-part.

Experience has shown that the symbols-in-versions file is very useful to
applications that want to build with a wide range of libcurl versions.
It is however easy to get it wrong and the source gets a bit messy with
all the fixed numerical comparisions.

The point of this script is to provide an easy-to-use macro for libcurl-
using applications to do preprocessor checks for specific libcurl
defines, and yet make the code clearly show what the macro is used for.

Bugfix: https handshake fails using gnutls 3 on windows
http://sourceforge.net/tracker/index.php?func=detail&aid=3441084&group_id=976&atid=100976

New gnutls versions have an error handler that knows about Winsock
errors, which is why gnutls_transport_set_global_errno() was deprecated
and then removed.

This is a correction of commit f5bb3701 (blame me) which meant to
reimplement gnutls_transport_set_global_errno(), which is not necessary.

Regression: commit b998d95b (shipped first in release 7.22.0) made the
condition always equal false that should reset the TIMER_CONNECT timer
and call the Curl_verboseconnect() function.

Reported by: "Captain Basil"
Bug: http://curl.haxx.se/mail/archive-2011-11/0035.html

A regression between 7.22.0 and 7.23.0 -- downloading a file with the
flags -O and -J results in the content being written to stdout if and
only if there was no Content-Disposition header in the http response. If
there is a C-D header with a filename attribute, the output is correctly
written.

Reported by: Dave Reisner
Bug: http://curl.haxx.se/mail/archive-2011-11/0030.html

Related to the f64812ca commit

prefixing a command with '*' means it is allowed to fail without
aborting the chain actions

Also, check for the session sharing bit instead of comparing pointers