Provide a mechanism for configuring the SAXParserFactory

[ndw]

The default way to construct a parser (for example, to read the cache) is to use SAXParserFactory.newInstance() which relies on the global machinery.

The problem with JAXP is that it sets options globally for the whole application, and if one small part of the application relies on using the SAXParserFactory system properties for its option settings, that can break other parts of the application that also do XML parsing.

Add some mechanism(s) for configuring the parser in a way that doesn't rely on global properties.