Issue with SAXParserFactory

[cowtowncoder]

(reported by Charles Foster)

When I don't set "javax.xml.parsers.SAXParserFactory"

calling:

new com.fasterxml.aalto.sax.SAXParserFactoryImpl().newSAXParser()

gets me a:

com.fasterxml.aalto.sax.SAXParserImpl

but calling:

com.fasterxml.aalto.sax.SAXParserFactoryImpl.newInstance().newSAXParser()

gets me a:

com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl

[cowtowncoder]

This is because 'newInstance' is actually defined in SAXParserFactory, not in Impl.
Usage actually does not make much sense, since if impl class is already known, one could as well just call constructor. But just to reduce likelihood of usage problem, I'll add similar static method in SAXParserFactoryImpl class.