% h=more_hash(vargin)
%   Hash table declaration 
%   Creates and returns a hash object
%
%   USSAGE:
%
%   H = more_hash;
%   H('key') = value; %assign value to key
%   v = H('key');     % retrieve value for a key
%   H.keys            % return cell array of keys
%   H. values         % return array of values
%   H.idx             % returns sparse matrix of indexes
%
%   Remark:
%   The hash function used is sum of the key.
%   It can easilly be changed if needed.
