[AndyB] Auto move by prefix 1.1

Auto moves threads based on thread prefix.

This add-on is very useful to automatically move threads from a classified forum where the item has been sold to an archive forum.

(Example of Options page)

Questions and Answers:
Q: When are threads moved?
A: Threads which meet the options criteria will be moved at the top of every hour.

Q: The options indicates "Threads older than this many hours", is this the thread start date or last post date?
A: Last post date.