ENH: remove reliance on the Xfer class (issue #639)

This class is largely a pre-C++11 holdover. It is now possible to
simply use move construct/assignment directly.

In a few rare cases (eg, polyMesh::resetPrimitives) it has been
replaced by an autoPtr.

src/OpenFOAM/algorithms/indexedOctree/treeDataCell.C

@@ -104,12 +104,12 @@ Foam::treeDataCell::treeDataCell
 (
     const bool cacheBb,
     const polyMesh& mesh,
-    const Xfer<labelList>& cellLabels,
+    labelList&& cellLabels,
     const polyMesh::cellDecomposition decompMode
 )
 :
     mesh_(mesh),
-    cellLabels_(cellLabels),
+    cellLabels_(std::move(cellLabels)),
     cacheBb_(cacheBb),
     decompMode_(decompMode)
 {