notifications for various emergency situations

Having the '!' on structures when they're missing wood is helpful, there have been multiple times when I've missed that my nobles don't have the material to craft something.
I've also almost lost a villager to starvation because I'd accidentally caused them to strand themself up on a ledge with no way down, and I didn't notice for ages because I couldn't see them inside the mine.

A small feed for pathing errors or halted production might be helpful if there isn't a more intuitive way to solve this.