This program need zlib. It's not contained in the project.

This program need zlib. But It's not contained in the project. 
And in windows10 vs2015,  we should add ZLIB_WINAPI before include zlib.h.  
If not, this will produce link error "can not found _crc32 to link"
more info: https://zlib.net/DLL_FAQ.txt
```
#define ZLIB_WINAPI
#include "zlib.h"
```