void silc_hash_table_rehash_ext(SilcHashTable ht, SilcUInt32 new_size,
                                    SilcHashFunction hash,
                                    void *hash_user_context);

    Rehashs the hash table. The size of the new hash table is provided
    as `new_size'. If the `new_size' is zero then this routine will make
    the new table of a suitable size. Note that this operation may be
    very slow.

    The `hash' and `hash_user_context' are application specified hash
    function. If not provided the hash table's default is used.