PrincipalConnectors: Another schema/documentation/code mismatch.

[Rod Widdowson]

We have had a few of these, so I should have a process established for it,
but I don't.  Anyway I think that it is important to ensure that this
information is aired publicly.

It turns out that the schema for the Transient principal connectors
specified an attribute:

                <attribute name="noResultIsError" type="boolean">
                    <annotation>
                        <documentation>
                            A boolean flag indicating whether a query
returning no results should be considered an error. 
                            Default value is false.
                        </documentation>
                    </annotation>
                </attribute>

This is not implemented in V2, and not documented anywhere (except the
schema).  

It turns out that this would be easy to implement in the V3 framework (we
have distinguished errors), but is it worth it?

My instinct says no.  This begs the next question: whether we should remove
this from the schema?  Again my instinct is no, but that I should amend the
<documentation>.

/Rod