adding database schema
seek_secret table became games, getting back game_id and other stuffs
Updating table_files dependency and improving indentation in src/Makefile
Now adding game_id in doors, door_discovery, scorrs, scorr_discovery
including reference in database diagram
Now enforcing references for door_discovery and doors, also making sure in test_db that for every game all fields are strictly positive (table weren't created sometimes because the random_number was 0)
Changing names for annex tables in order to be shorter, more convenient and more appropriate to what they mean. Game id also handled by both scorr tables now.
Updating the fields of games table, some fields are not handled now, but all that is needed now is to complete the code of the associated getters
Modifying nethack's Makefile and activating again NETHACK_ACCESS, new database seems to work, even with concurrent access.
Merge remote-tracking branch 'origin/improve_db' into dev