Saxon extensions to the W3C XSLT/XQuery specifications

A new extension attribute saxon:allow-all-built-in-types="yes" has been added to enable the use of types such as xs:int which are not permitted by the W3C conformance rules for a Basic XSLT Processor. These types are already allowed by Saxon-SA, of course, but this switch also enables their use with Saxon-B. The particular use case that prompted this extension was Dimitre Novatchev's XPath 2.0 Visualizer tool, which uses dynamically-constructed XSLT stylesheets as a vehicle for exercising XPath expressions.