Assume C++11 support

Remove all CMake checks for C++11 support since we now assume that we have it.
Replace all polyvox_* macros with standard C++ names.

See #48

library/PolyVoxCore/source/ArraySizes.cpp

@@ -23,6 +23,8 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxCore/ArraySizes.h"
 
+#include <cstdint>
+
 namespace PolyVox
 {	
 	/**