DataImportHandler; reload-config; response in case of failure & further requests

Reloading while the config-file is valid is completely fine, but if the config is broken - the Response is plain HTML, containing the full stacktrace (see attachment). further requests contain a status Element with DataImportHandler started. Not Initialized. No commands can be run, but respond with a HTTP-Status 200 OK :/

Would be nice, if:

• the response in case of error could also be xml formatted
• contain the exception message (in my case The end-tag for element type "entity" must end with a '>' delimiter.) in a seperate field
• use a better/correct http-status for the latter mentioned requests, i would suggest 503 Service Unavailable

So we are able to display to error-message to the user, while the config gets broken - and for the further requests we could rely on the http-status and have no need to check the content of the xml-response.