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=

src/Nazara/BulletPhysics3D/BulletCollider3D.cpp

@@ -386,7 +386,7 @@ namespace Nz
 
 	void BulletNullCollider3D::ComputeInertia(float /*mass*/, Vector3f* inertia) const
 	{
-		inertia->Set(1.f, 1.f, 1.f);
+		*inertia = Vector3f::Unit();
 	}
 
 	btCollisionShape* BulletNullCollider3D::GetShape() const