* iface/gspn/ssp.cc (couvreur99_check_shy_ssp::find_state,
numbered_state_heap_ssp_semi): Implement a double hash_map using greatspn's new container() function. * iface/gspn/ssp.hh (gspn_ssp_interface): Add a doublehash option. * iface/gspn/ltlgspn.cc: Add option -1 to disable this optimization.