Extracts wrong name when used with webpack

Webpack uses query strings for it loaders.
When executing webpack code with source maps and _pretty-error_ I get invalid file names:

```
- loader.js:10 eval
/a/path/template.jade?/a/path/loader.js:10:57
```

I would expect `template.jade` however pretty error displays `loader.js`.

Start with the webpack and source-map reproduction described in the issue, focusing on the displayed path containing a query string. Trace how pretty-error extracts the filename from that path. Done when the output reports template.jade rather than loader.js.

Written by the indexing model from the issue text.