v2.4 Windows support

Experimental Windows WCHAR -> utf8 update to support non-Latin filenames for Windows, e.g. "pigz Описание.pdf "

CMake does not work for Windows. To compile for Windows using the Microsoft C++ (MSVC) compiler

1. Launch the "x64 Native Tools Command Prompt"
2. Use 'cd' to change directory to ..\pigz\src\win
3. Run the command 'msvc.bat'

For MacOS/Linux both configure and CMake work.

Included are Windows executables build for both the default and faster CloudFlare zlib.

v2.4 Cloudflare

pigz version 2.4 built with Cloudflare zlib