Blubber does not currently validate user-provided configuration beyond what go-yaml inherently provides, hence errors related to bad config are very obscure. Let's see about implementing:
- Wrapping of YAML parsing errors (type errors, mostly) to be more user friendly
- Definition/implementation of a validation interface for config parts
- Errors upon missing config elements required by other config, etc.
- Errors upon unknown YAML config elements (they are currently just ignored by the YAML parser)