added C++0x-style cbegin(), cend() iterator methods

- added STL-compatible resize() method.
  Should this be the primary entry point?

- made [DS]LListBase end iterators private

src/OpenFOAM/containers/HashTables/HashTable/HashTable.H

@@ -384,6 +384,12 @@ public:
         };
 
 
+        //- const_iterator set to the beginning of the HashTable
+        inline const_iterator cbegin() const;
+
+        //- const_iterator set to beyond the end of the HashTable
+        inline const const_iterator& cend() const;
+
         //- const_iterator set to the beginning of the HashTable
         inline const_iterator begin() const;