Add tile log analysis

This adds a process which runs a cron job processing the tile logs into summaries of "z/x/y count" daily.
I didn't even know about `-A` ;-) I only ever get a backup file when I forgot to add a new file as soon as I create it and I then like the status output to show so I know to remove it ratehr than leaving it cluttering things up.

It's entirely a matter of personal choice and modes of operation unfortunately, so there's no easy answer :-(