#include header for time() on Windows

src/physac.h

@@ -255,6 +255,7 @@ PHYSACDEF void ClosePhysics(void);
     // Functions required to query time on Windows
     int __stdcall QueryPerformanceCounter(unsigned long long int *lpPerformanceCount);
     int __stdcall QueryPerformanceFrequency(unsigned long long int *lpFrequency);
+    #include <time.h>
 #elif defined(__linux__)
     #if _POSIX_C_SOURCE < 199309L
         #undef _POSIX_C_SOURCE