Fix stdbool.h include for VS 2013 and higher
@@ -38,7 +38,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#define NULL 0
#endif
-#if defined(HAVE_STDBOOL_H)
+#if defined(HAVE_STDBOOL_H) || (defined(_MSC_VER) && _MSC_VER >= 1800)
#include <stdbool.h>
#else
#ifndef __cplusplus
