Hardening/619 forbidden characters

### Description
o The response to 'Service not found: $URL' changed to 'unrecognized request', to avoid to respond with the data that the user supplied (security risk)
o Requests with any of the 'forbidden characters' in the values of the payload (see issue #619) are refused, both for XML and JSON.

invalid -> valid for all the new file that are invalid for the broker but valid for XSD.
A small headache we have here now ...
It was easier before when the broker fulfilled 100% of the XSD.

However, "fixed" in b1c608c