Physics/Geom: Fix missing initialization/uninitialization (fixes crash at exit)

Former-commit-id: 94e4ec331cd559ba4a2680f36325f25a7d2333f2

include/Nazara/Physics/Geom.hpp

@@ -39,6 +39,9 @@ namespace Nz
 
 	class NAZARA_PHYSICS_API PhysGeom : public RefCounted
 	{
+		friend PhysGeomLibrary;
+		friend class Physics;
+
 		public:
 			PhysGeom() = default;
 			PhysGeom(const PhysGeom&) = delete;
@@ -64,6 +67,9 @@ namespace Nz
 		protected:
 			virtual NewtonCollision* CreateHandle(PhysWorld* world) const = 0;
 
+			static bool Initialize();
+			static void Uninitialize();
+
 			mutable std::unordered_map<PhysWorld*, NewtonCollision*> m_handles;
 
 			static PhysGeomLibrary::LibraryMap s_library;