Improve math module (#396)

* Improve math module

- Mark almost everything constexpr
- Equality (a == b) is now exact, down to the bit level. If you want approximate equality use the new ApproxEqual method/static method
- Rename Nz::Extend to Nz::Extent
- Removed Make[] and Set[] methods in favor of their static counterpart and operator=

tests/UnitTests/Engine/Math/RayTest.cpp

@@ -67,12 +67,12 @@ SCENARIO("Ray", "[MATH][RAY]")
 
 			THEN("For the bounding volume collision's")
 			{
-				Nz::BoundingVolumef nullVolume(Nz::Extend::Null);
+				Nz::BoundingVolumef nullVolume(Nz::Extent::Null);
 				CHECK(!ray.Intersect(nullVolume));
 
 				float tmpClosest = -1.f;
 				float tmpFurthest = -1.f;
-				Nz::BoundingVolumef infiniteVolume(Nz::Extend::Infinite);
+				Nz::BoundingVolumef infiniteVolume(Nz::Extent::Infinite);
 				CHECK(ray.Intersect(infiniteVolume, &tmpClosest, &tmpFurthest));
 				CHECK(tmpClosest == Catch::Approx(0.f));
 				CHECK(tmpFurthest == std::numeric_limits<float>::infinity());