* refactor the XPath engine code so that we use an interface for the 
    XPathEngine.
    Then we can allow plug-in XPath engines, such as Xalan, SAXON and JPath...
    Also if we integrate the JPath project from jakarta-commons
    we can perform XPath over Java Beans as well as dom4j, DOM, JDOM etc.

* implement more XSLT elements

* make standard (XSLT) build process for turning XSLT documents into xtags JSP documents

* consider document creation tags like?
    <xtags:document name="foo.xml">
        <xtags:element name="root">
            <xtags:attribute name="a">value of a</xtags:attribute>
            <xtags:element name="child">
                this is some text
            </xtags:element>
        </xtags:element>
    </xtags:document>