Header reshapery, outlaw stdlib using wrong math.

* For platforms that don't care about casing such as
  all but Linux platforms, there was a big oh-whoopsie
  if the current header search path had a Math.h in it,
  in this case, it was <OpenVDB/Math/Math.h>, and well,
  obviously the cstd library doesn't appreciate that very
  much!
* so we therefore yeeted OpenVDB/Math out of the ever-finding
  search path, and you are now forced to prefix that include, I
  suppose we could have just renamed it too but it seems fine.

Sources/OpenVDB/include/openvdb/math/Operators.h

@@ -6,10 +6,10 @@
 #ifndef OPENVDB_MATH_OPERATORS_HAS_BEEN_INCLUDED
 #define OPENVDB_MATH_OPERATORS_HAS_BEEN_INCLUDED
 
-#include "math/FiniteDifference.h"
-#include "math/Stencils.h"
-#include "math/Maps.h"
-#include "math/Transform.h"
+#include "openvdb/math/FiniteDifference.h"
+#include "openvdb/math/Stencils.h"
+#include "openvdb/math/Maps.h"
+#include "openvdb/math/Transform.h"
 #include <cmath> // for std::sqrt()
 
 

Sources/OpenVDB/include/openvdb/math/Ray.h

@@ -10,9 +10,9 @@
 #ifndef OPENVDB_MATH_RAY_HAS_BEEN_INCLUDED
 #define OPENVDB_MATH_RAY_HAS_BEEN_INCLUDED
 
-#include "math/Math.h"
-#include "math/Vec3.h"
-#include "math/Transform.h"
+#include "openvdb/math/Math.h"
+#include "openvdb/math/Vec3.h"
+#include "openvdb/math/Transform.h"
 #include <algorithm> // for std::swap()
 #include <iostream> // for std::ostream
 #include <limits> // for std::numeric_limits<Type>::max()