Right now we display an error dialog if there was an exception parsing the settings.

We should potentially also add the exception test to that dialog, so the user can see exactly where the parsing went wrong.

This is also dependent upon #475, where I'm adding support for jsoncpp, We can throw an exception with a decent message there, but we need to make sure it's actually displayed.

Preferably, the exception text would

1. Be copyable
2. Be collapsible (so the user sees our message first, then can expand the "details")