Revert a wrong change introduced in MR 546

A prerequisite to create physics objects for statics was to remove the
dependency on base node (since it doesn't yet exists) for object
position. It is still necessary for animation though.

Restore the basenode (and the associated FIXME) so that animated objects works properly.

apps/openmw/mwphysics/object.cpp

@@ -116,9 +116,6 @@ namespace MWPhysics
         if (mShapeInstance->mAnimatedShapes.empty())
             return false;
 
-        if (mPtr.getRefData().getBaseNode() == nullptr)
-            return true;
-
         assert (mShapeInstance->getCollisionShape()->isCompound());
 
         btCompoundShape* compound = static_cast<btCompoundShape*>(mShapeInstance->getCollisionShape());

apps/openmw/mwworld/scene.cpp

@@ -122,6 +122,8 @@ namespace
             const ESM::RefNum& refnum = ptr.getCellRef().getRefNum();
             if (!refnum.hasContentFile() || pagedRefs.find(refnum) == pagedRefs.end())
                 ptr.getClass().insertObjectRendering(ptr, model, rendering);
+            else
+                ptr.getRefData().setBaseNode(new SceneUtil::PositionAttitudeTransform); // FIXME remove this when physics code is fixed not to depend on basenode
 
             setNodeRotation(ptr, rendering, rotation);