I've fixed some bugs with the mail system and added some new things:

- LETTERLIST marks new letters that you have yet to open.
- Letters are now returned to the sender after 10 days, if it is unable to deliver due to the recipient being unavailable.
* This one is likely going to be interesting in 10 days, there's a loooot of backlog.
- CHAR and DIP and PRESERVE now modify the letter description in full again.
- Delivery of mail might have some wonky messages for a bit, but it'll sort itself out with new letters going forward.
- New letters from crafters, auctions, and such, now mark themselves as so on LETTERLIST.

Penned by my hand on Gosday, the 1st of Khepary, in the year 492 MA.