Changed for 1.7.9 (getName becomes getUniqueId)

Changed:
    public InventoryDB() {
        dataDir = new File(iConomy.Server.getWorlds().get(0).getName(), "players");
    }
To:
    public InventoryDB() {
        dataDir = new File(iConomy.Server.getWorlds().get(0).getUniqueId(), "players");
    }