Add exception handling

Here is the patch.

I found a problem with my patch, and I'm working on an updated one.

Here's an updated patch, removing the unrelated addition of providing a human readable description (I'll create a new issue for that) and based on the latest changes in dev.

Okay, here's one that actually includes the latest changes in dev, and a forgotten use statement.

I've committed these changes. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.