Fixed minor compile errors:

- Lack of <functional> in AStarPathfinder.h
 - Lack of <cstdint> in several files (why did this compile on GCC?)

library/PolyVoxCore/include/PolyVoxCore/Impl/SubArray.h

@@ -26,6 +26,8 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxCore/Impl/TypeDef.h"
 
+#include <cstdint>
+
 namespace PolyVox
 {
 	template <uint32_t noOfDims, typename ElementType> class Array;

library/PolyVoxCore/include/PolyVoxCore/Impl/Utility.h

@@ -26,6 +26,8 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxCore/Impl/TypeDef.h"
 
+#include <cstdint>
+
 namespace PolyVox
 {
 	POLYVOX_API uint8_t logBase2(uint32_t uInput);