http_digest: Moved clean-up function into SASL module
http_digest: Moved challenge decoding into SASL module
http_digest: Moved response generation into SASL module
http_digest: Fixed compilation errors from commit 6f8d8131b1

error: invalid operands to binary
warning: pointer targets in assignment differ in signedness
sasl: Fixed HTTP digest challenges with spaces between auth parameters

Broken as part of the rework, in commit 7e6d51a73c, to assist with the
addition of HTTP digest via Windows SSPI.
sasl: Fixed compilation warning from commit 25264131e2

Added forward declaration of digestdata to overcome the following
compilation warning:

warning: 'struct digestdata' declared inside parameter list

Additionally made the ntlmdata forward declaration dependent on
USE_NTLM similar to how digestdata and kerberosdata are.
http_digest: Fixed memory leaks from commit 6f8d8131b1
contributors.sh: split lists using " and "

... and require the space after the filtering to make the filter able to
remove names.
THANKS-filter: added another Michał Górny version we've used
tool_strdup.c: include the tool strdup.h

... not the lib/ one that the tool no longer uses!
build: Fixed Visual Studio project file generation of strdup.[c|h]

As the curl command-line tool now includes it's own version of strdup(),
for platforms that don't have it, fixed up the git respository Visual
Studio project file generator to not include the version from lib in the
tool project files, rather than having both lib\strdup.[c|h] and
src\tool_strdup.[c|h] present.
curl_easy_setopt.3: add CURLOPT_PINNEDPUBLICKEY

Reported-by: Christian Hägele
Bug: http://curl.haxx.se/mail/lib-2014-11/0078.html
RELEASE-NOTES: synced with 68542e72a9
contributors.sh: --releasenotes reads in names from RELEASE-NOTES

This is very handy when updating the RELEASE-NOTES as then we sometimes
have names added manually in the existing list and we use this script to
update the set.
http_digest: Added required SSPI based variables to digest structure
http_digest: Added SSPI based authentication functions

This temporarily breaks HTTP digest authentication in SSPI based builds,
causing CURLE_NOT_BUILT_IN to be returned. A follow up commit will
resume normal operation.
http_digest: Added SSPI based clean-up code
http_digest: Added SSPI based challenge decoding code
sasl_sspi: Added HTTP digest response generation code
sasl: Removed non-SSPI Digest functions and defines from SSPI based builds

Introduced in commit 7e6d51a73c these functions and definitions are only
required by the internal challenge-response functions now.