JAXP interface (transformation, XPath, schema processing)

From 12.2, in response to bug #5953, we have changed the Saxon implementation of the JAXP ValidationHandler interface, so that a call on XMLReader.parse() using this ValidationHandler does not throw an exception if the document is found to be invalid. Although the JAXP specification is unspecific on what should happen, this is the way Xerces behaves, and since the main rationale for providing this API is for interoperability with Xerces, we decided to bring it into line. To determine whether validation was successful you should now monitor calls on the supplied ErrorHandler; if you use the StandardErrorHandler (or a subclass) then you can call getErrorCount() at the end of the validation run.