Filter errors

We get a lot of noise from code we don't care so much about such as random chrome extensions or occasionally bad third party scripts which we can't do anything about.

```
ReferenceError: GLOBALS is not defined at Gmail (chrome-extension://edmfnamdkbpibmfhghablbnabapbaflf/gmail.js:13:27) at (:1:13)
```

I wondered if it'd be possible to only log errors which originate from first party scripts; I guess supporting an option which allows errors to be filtered out might worth for this?