As this is mandated by the http2 spec draft-09

This patch chooses different approach to integrate HTTP2 into HTTP curl
stack. The idea is that we insert HTTP2 layer between HTTP code and
socket(TLS) layer. When HTTP2 is initialized (either in NPN or Upgrade),
we replace the Curl_recv/Curl_send callbacks with HTTP2's, but keep the
original callbacks in http_conn struct. When sending serialized data by
nghttp2, we use original Curl_send callback. Likewise, when reading data
from network, we use original Curl_recv callback. In this way we can
treat both TLS and non-TLS connections.

With this patch, one can transfer contents from https://twitter.com and
from nghttp2 test server in plain HTTP as well.

The code still has rough edges. The notable one is I could not figure
out how to call nghttp2_session_send() when underlying socket is
writable.

Add ALPN support when using GnuTLS >= 3.2.0. This allows
libcurl to negotiate HTTP/2.0 for https connections when
built with GnuTLS.

See:
http://www.gnutls.org/manual/gnutls.html#Application-Layer-Protocol-Negotiation-_0028ALPN_0029
http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-04

Add ALPN support when using OpenSSL. This will offer ALPN and NPN to the
server, who can respond with either one or none of the two. OpenSSL >=
1.0.2 is required, which means as of today obtaining a snapshot from
ftp://ftp.openssl.org/snapshot/.

See:
http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-04
https://github.com/openssl/openssl/blob/ba168244a14bbd056e502d7daa04cae4aabe9d0d/ssl/ssl_lib.c#L1787

no previous prototype for function 'memory_tracking_init'

The test contains a cookie jar file where one of the cookies has an
expiry date of 1391252187 -- Sat, 1 Feb 2014 10:56:27 GMT which has
now expired. Updated to Wed, 14 Oct 2037 16:36:33 GMT as per test
179.

Reported-by: Adam Sampson
Bug: http://curl.haxx.se/bug/view.cgi?id=1330

In preparation for adding URL specific options moved the initialisation
of the Configurable structure into a separate function in tool_cfgable.

Since the timer resolution is lower, there are actually cases that
the compared values are equal. Therefore we check for previous
timestamps being greater than the current one instead.

Since the output isn't actually being written in text-mode and it
was rather used as a workaround, disable text-mode for these tests.

According to section 2.2 of RFC959 the End-of-Line is defined as:
 The end-of-line sequence defines the separation of printing
 lines.  The sequence is Carriage Return, followed by Line Feed.

Verified by sniffing traffic between a Windows FTP client (FileZilla)
and Unix-hosted FTP server (ProFTPD).

It makes more sense to convert the expected output to [CR][LF] on
Windows than to force the actual, probably correct, output to [LF].

This way it is actually possible to see if curl outputs the correct
line-ending excepted by a text-aware test case.

For some reason Windows 7 SP1 chooses TLS 1.0 instead of TLS 1.2
if it is not explicitly enabled within grbitEnabledProtocols.

More information can be found on MSDN:
http://msdn.microsoft.com/library/windows/desktop/aa379810.aspx