Added the removal of the locally generated project files so one
may revert to a clean repository.

In preparation for adding the test suite and examples projects renamed
the top level "all" solution files to better describe what they are.

This will also enable us to use "curl" rather than "curlsrc" for the
command line tool solution and project files, which will simplify some
of the configuration.

Defined the DEBUGBUILD pre-processor variable to allow extra logging,
which is particularly useful in debug builds, as we use this and Visual
Studio typically uses _DEBUG.

We could define DEBUBBUILD, in curl_setup.h, when _MSC_VER and _DEBUG is
defined but that would also affect the makefile based builds which we
probably don't want to do.

And modify the text to refer to HTTP 2 as it isn't called "2.0".

Reported-By: Michael Wallner

curl_sasl.c:1506: warning: unused variable 'chlg'

curl_sasl.c:1317: warning: unused parameter 'conn'

Added Curl_des_set_odd_parity() for use when cryptography engines
don't include this functionality.

Possible access to uninitialised memory '&nread' at line 140 of
lib/security.c in function 'ftp_send_command'.

Reported-by: Rich Burridge

  Its use is only enabled by explicit requirement in URL (;AUTH=EXTERNAL) and
by not setting the password.

Modified the Curl_ossl_cert_status_request() function to return FALSE
when built with BoringSSL or when OpenSSL is missing the necessary TLS
extensions.

Fixed the build of openssl.c when OpenSSL is built without the necessary
TLS extensions for OCSP stapling.

Reported-by: John E. Malmberg

... as that is ancient history and not used.

Also known as "status_request" or OCSP stapling, defined in RFC6066
section 8.

Thanks-to: Joe Mason
- for the work-around for the OpenSSL bug.

HAVE_BORINGSSL gets defined now by configure and should be defined by
other build systems in case a BoringSSL build is desired.

Commit 7a8b2885 made some functions static and removed the public
Curl_ prefix. Unfortunately, it also removed the sasl_ prefix, which
is the naming convention we use in this source file.

packages/vms/gnv_link_curl.com was assuming only a single letter suffix
in the openssl version.  That assumption has been fixed for 7.40.