Update Windows PHP-SDK binary tools

Hi!

I my opinion, it would be good to offer an up-to-date
php-sdk-binary-tools-2015MMDD.zip on
<http://windows.php.net/downloads/php-sdk/>.  Currently the latest
version is nearly four years old and contains rather old versions of the
binaries, accordingly.  Especially, phpsdk_setvars.bat is completely
outdated, and creates trees for VC 6 and VC 8, but not for VC 11 or even
VC 14.  The how-to "Build your own PHP on Windows"[1] mentions the
issue, so that it's not a real problem, but it would be nice to make
building on Windows as easy as possible[2].

I'm gladly willing to help with this, but I don't know if there's a
public repo, or some documents describing where to get the binaries
resp. how to build them, etc.

[1] <https://wiki.php.net/internals/windows/stepbystepbuild>
[2] <http://chat.stackoverflow.com/transcript/message/23563126#23563126>

-- 
Christoph M. Becker