Mayaqua: use included zlib headers only on Windows

zlib doesn't have a dedicated directory on Unix systems, because it has a single header, meaning that the header from the repository was being used instead.

This commit moves the header to the Windows includes directory, so that we can use the proper include path on all systems.

src/Mayaqua/Memory.c

@@ -120,7 +120,7 @@
 #include <stdarg.h>
 #include <time.h>
 #include <errno.h>
-#include <zlib/zlib.h>
+#include <zlib.h>
 #include <Mayaqua/Mayaqua.h>
 
 #define	MEMORY_SLEEP_TIME		150