Split error reporting

[dizzzz]

When fn:error() is called an error is logged in exist.log and the issue is visible via the jms:report() function.

Decide what to do:

• either record XPathExceptions/fn:error separate from other problems -> do not mark as real issue, for info only
• have fn:error() to stop receiving messages (and mark message as not received)

I think the 2nd option would be most logical since there is no good way to do it in an other way. When possible

[dizzzz]

as part of the change, the error listener and the normal listener can be combined.
upon certain exceptions, the Receiver.close() shall be called