Update to the indexes for regions This commit: 1) Uniforms the definition of constraints for technology groups to constraints for single technology concerning the association to the regions index. 2) Removes the automatic permutation of the region names to obtain all the possible regions combination, since it caused instability when dealing with more than 10 regions. If more regions are associated with an item, the region combination must be added to the regions table. 3) Fixes other minor issues.