xfer class modifications:

- removed operator* in favour of operator() for consistency with tmp
    class. The previous use of operator() for const casting didn't work
    anyhow due to template confusion.
  - added xferCopy(), xferMove() and xferTmp() template functions instead
  - preliminary changes to IOobjects and Fields for xfer

src/OpenFOAM/containers/HashTables/HashTable/HashTable.C

@@ -93,7 +93,7 @@ HashTable<T, Key, Hash>::HashTable(const xfer<HashTable<T, Key, Hash> >& ht)
     endIter_(*this, NULL, 0),
     endConstIter_(*this, NULL, 0)
 {
-    transfer(*ht);
+    transfer(ht());
 }