Fixed a problem with sending usernames and passwords that contain
backslash, quotation mark and space characters.

... on Snow Leopard and Lion

Snow Leopard introduced the SSLSetSessionOption() function, but it
doesn't disable peer verification as expected on Snow Leopard or
Lion (it works as expected in Mountain Lion). So we now use sysctl()
to detect whether or not the user is using Snow Leopard or Lion,
and if that's the case, then we now use the deprecated
SSLSetEnableCertVerify() function instead to disable peer verification.

... and have it take a proper 'struct connectdata *' as first argument

... it also clobbered the 'result' return value so that it wouldn't
return the error back to the parent function properly, which broke test
809 when run with 'multi-always'.

When prefixing a path with /~/ it is supposed to be used relative to the
user's home directory but it didn't work. Now we cut off the entire
three byte sequenct "/~/" which seems to be how OpenSSH does it.

Bug: http://curl.haxx.se/bug/view.cgi?id=1173
Reported by: Balaji Parasuram

Also reverts commit f254c59d

The Clang compiler found a few implicit conversion problems that have
now been fixed.

Issue: When building a 32bit target with large file support HP-UX
<sys/socket.h> header file may simultaneously provide two different
sets of declarations for sendfile and sendpath functions, one with
static and another with external linkage. Given that we do not use
mentioned functions we really don't care which linkage is the
appropriate one, but on the other hand, the double declaration emmits
warnings when using the HP-UX compiler and errors when using modern
gcc versions resulting in fatal compilation errors.

Mentioned issue is now fixed as long as we don't use sendfile nor
sendpath functions.

Inclusion of top two most included header files now done in setup_once.h

Some HP-UX system headers require TRUE defined to 1 and FALSE to 0.

Remove all system file includes from this file as they're not needed

Reported by: Dan Fandrich

A bundle is a list of all persistent connections to the same host.
The connection cache consists of a hash of bundles, with the
hostname as the key.
The benefits may not be obvious, but they are two:

1) Faster search for connections to reuse, since the hash
   lookup only finds connections to the host in question.
2) It lays out the groundworks for an upcoming patch,
   which will introduce multiple HTTP pipelines.

This patch also removes the awkward list of "closure handles",
which were needed to send QUIT commands to the FTP server
when closing a connection.
Now we allocate a separate closure handle and use that
one to close all connections.

This has been tested in a live system for a few weeks, and of
course passes the test suite.

BLANK_AT_MAKETIME may be used in our Makefile.am files to blank
LIBS variable used in generated makefile at makefile processing
time. Doing this functionally prevents LIBS from being used for
all link targets in given makefile.

This handling already works with the easy-interface code. When a request
is sent on a re-used connection that gets closed by the server at the
same time as the request is sent, the situation may occur so that we can
send the request and we discover the broken connection as a RECV_ERROR
in the PERFORM state and then the request needs to be retried on a fresh
connection. Test 64 broke with 'multi-always-internally'.

Currently, LIBS is already used through other macros.

Although it is not explicitly stated in the documentation, NSS uses
*pRetCert and *pRetKey even if the client authentication hook returns
a failure.  Namely, if we destroy *pRetCert without clearing *pRetCert
afterwards, NSS destroys the certificate once again, which causes a
double free.

Reported by: Bob Relyea

.. that are sent when auth-negotiating before a chunked
upload or when setting the 'Transfer-Encoding: chunked'
header and intentionally sending no content.

Adjust test565 and test1333 accordingly.

the newly introduced hostcheck.h/c is missing in the Visual Studio
Makefiles as obj file.

Bug: http://curl.haxx.se/mail/lib-2012-11/0176.html

The conversions from ssize_t to int need to be typecasted.

DNS cache entries populated with CURLOPT_RESOLVE were not properly freed
again when done using the multi interface.

Test case 1502 added to verify.

Bug: http://curl.haxx.se/bug/view.cgi?id=3575448
Reported by: Alex Gruz

If we use memory functions (malloc, free, strdup etc) in C sources in
libcurl and we fail to include curl_memory.h or memdebug.h we either
fail to properly support user-provided memory callbacks or the memory
leak system of the test suite fails.

After Ajit's report of a failure in the first category in http_proxy.c,
I spotted a few in the second category as well. These problems are now
tested for by test 1132 which runs a perl program that scans for and
attempts to check that we use the correct include files if a memory
related function is used in the source code.

Reported by: Ajit Dhumale
Bug: http://curl.haxx.se/mail/lib-2012-11/0125.html

Fixed checksrc warnings

Re-send ACK for block X in case we receive block X data again while
waiting for block X+1.

Based on an earlier patch by Marcin Adamski.

It either causes increased memory usage or exposes users
to the "CRIME attack" (CVE-2012-4929)