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In a few rare cases (eg, polyMesh::resetPrimitives) it has been
replaced by an autoPtr.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

@@ -86,11 +86,11 @@ Foam::treeDataFace::treeDataFace
 (
     const bool cacheBb,
     const primitiveMesh& mesh,
-    const Xfer<labelList>& faceLabels
+    labelList&& faceLabels
 )
 :
     mesh_(mesh),
-    faceLabels_(faceLabels),
+    faceLabels_(std::move(faceLabels)),
     isTreeFace_(mesh.nFaces(), 0),
     cacheBb_(cacheBb)
 {