... in case runtests.pl is invoked with non-default -b option

Fixes a regression caused by 1e29d275.

Update sharing interface documentation to provide exhaustive list of
what it does and does not share.

Most notable the security advisory:
http://curl.haxx.se/docs/adv_20130412.html

... and make 1216 also verify it with a file input

These tests verify commit 3604fde3d3c9b0d, the fix for the "cookie
domain tailmatch" vulnerability. See
http://curl.haxx.se/docs/adv_20130412.html

Cookies set for 'example.com' could accidentaly also be sent by libcurl
to the 'bexample.com' (ie with a prefix to the first domain name).

This is a security vulnerabilty, CVE-2013-1944.

Bug: http://curl.haxx.se/docs/adv_20130412.html

The previously applied patch didnt work on Windows; we cant rely
on shell commands like 'echo' since they act diffently on each
platform and each shell.
In order to keep this script platform-independent the code must
only use pure Perl.

Test 1217 verifies commit e0fb2d86, and without that change this
test fails.

When doing PWD, there's a 257 response which apparently some servers
prefix with a comment before the path instead of after it as is
otherwise the norm.

Failing to parse this, several otherwise legitimate use cases break.

Bug: http://curl.haxx.se/mail/lib-2013-04/0113.html

The OpenSSL pipe wrote to the final CA bundle file, but the encoded PEM
output wrote to a temporary file.  Consequently, the OpenSSL output was
lost when the temp file was renamed to the final file at script finish
(overwriting the final file written earlier by openssl).
Patch posted to the list by Richard Michael (rmichael edgeofthenet org).

This test is an attempt to repeat the problem YAMADA Yasuharu reported
at http://curl.haxx.se/mail/lib-2013-04/0108.html

added "tcpkeepalive on Mac OS X"

I noticed that aria2's SecureTransport code disables insecure ciphers such
as NULL, anonymous, IDEA, and weak-key ciphers used by SSLv3 and later.
That's a good idea, and now we do the same thing in order to prevent curl
from accessing a "secure" site that only negotiates insecure ciphersuites.

MacOS X doesn't have TCP_KEEPIDLE/TCP_KEEPINTVL but only a single
TCP_KEEPALIVE (see
http://developer.apple.com/library/mac/#DOCUMENTATION/Darwin/Reference/ManPages/man4/tcp.4.html).
Here is a patch for CURLOPT_TCP_KEEPIDLE on OSX platforms.

1 - We don't use the results from the test and we never did. recvfrom()
is only used by the TFTP code and it has not caused any problems.

2 - the CURL_CHECK_FUNC_RECVFROM function is extremely slow

Previously it only compared credentials if the requested needle
connection wasn't using a proxy. This caused NTLM authentication
failures when using proxies as the authentication code wasn't send on
the connection where the challenge arrived.

Added test 1215 to verify: NTLM server authentication through a proxy
(This is a modified copy of test 67)

Since qsort implementations vary with regards to handling the order
of similiar elements, this change makes the internal sort function
more deterministic by comparing path length first, then domain length
and finally the cookie name. Spotted with testcase 62 on Windows.

This reverts commit e51b23c9.
As discussed on the mailinglist, this was not the correct approach.

WINSOCK only:
Since FD_CLOSE is only signaled once, it may trigger at the same
time as FD_READ. Data actually being available makes it impossible
to detect that the connection was closed by checking that recv returns
zero. Another recv attempt could block the connection if it was
not closed. This workaround abuses exceptfds in conjunction with
readfds to signal that the connection has actually closed.

Since commit 57aeabcc, it handles errors on the control connection
while waiting for the data connection better.

Test 591 and 592 are updated accordingly.

When doing PORT and upload (STOR), this function needs to extract the
file descriptor for both connections so that it will respond immediately
when the server eventually connects back.

This flaw caused active connections to become unnecessary slow but they
would still often work due to the normal polling on a timeout. The bug
also would not occur if the server connected back very fast, like when
testing on local networks.

Bug: http://curl.haxx.se/bug/view.cgi?id=1183
Reported by: Daniel Theron