archiving old accounts

added account archiving in to redis persistance, so that unused accounts are not loaded anymore
Well I think the way I saw it was that you might be reloading an account, and while that happens then it will be saved back as closed, but I see now that it's kind of useless, since that scenario won't happen. So it's fine to just reload it and let the next saveAll move it into the banker:accounts key. But on the off chance it crashes in between the reload and saveAll, then on the next launch it will simple need to reload it again, which isn't a bid deal.