some J3D/misc cleanup (#2628)

* some j3d cleanup

* begin using uintptr_t

* j3dgraphbase cleanup

* j3dgraphanimator cleanup

src/d/actor/d_a_obj_ari.cpp

@@ -729,7 +729,7 @@ cPhs__Step daObjARI_c::create() {
         }
 
         J3DModel* model = mpMorf->getModel();
-        model->setUserArea((u32)this);
+        model->setUserArea((uintptr_t)this);
         for (u16 i = 0; i < model->getModelData()->getJointNum(); i++) {
             if (i != 0) {
                 model->getModelData()->getJointNodePointer(i)->setCallBack(JointCallBack);