This field was never used. Since it is persisted as part of a map[string]interface{} it is pretty easy to remove it.
We set RawToString=true so that []uint8 => string when decoding an interface{}. We set the MapType so that map[interface{}]interface{} decodes to map[string]interface{}. Add tests to ensure that this doesn't break existing usages. Fixes #7223
Daniel Nephin