There are 2 major issues right now:

1. There are no line numbers that get associated with a JsonException. This is fixable if we switch to using the SAX API and build the DOM directly. Then we can feed in the config file one line at a time.

2. Some of the error messages output either by the main parser or the schema validator are terrible. In particular the schema validator. We need to look at this and see about making the error messages better. This will likely involve raising upstream rapidjson issues and probably doing upstream PRs.