HashTable changes

- make table power-of-two, but since it seems to give 1-2% performance
  improvement, maybe forget it too.

- remove two-argument form of hashing classes and do the modulus direclty
  within HashTable instead. This simplifies things a fair bit.

- migrate Hash<void*> from db/dlLibrary to primitives/hashes/Hash

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

@@ -108,18 +108,25 @@ class HashTable
 
     // Private data: size of table, the table and current number of elements
 
+        //- The current number of elements in table
+        label nElmts_;
+
         //- Number of primary entries allocated in table (not necessarily used)
         label tableSize_;
 
         //- The table of primary entries
         hashedEntry** table_;
 
-        //- The current number of elements in table
-        label nElmts_;
-
 
     // Private Member Functions
 
+        //- Return a canonical (power-of-two) size
+        static label canonicalSize(const label);
+
+        //- Return the hash index of the Key within the current table size.
+        //  No checks for zero-sized tables.
+        inline label hashKeyIndex(const Key&) const;
+
         //- Assign a new hashedEntry to a possibly already existing key
         bool set(const Key&, const T& newElmt, bool protect);