Added a function to look up a definition of a named pattern.
Added a function to look up child elements and attributes.
Added wrapper functions to look up child elements and attributes.
Added a function to look up attribute values.
Added a function to look up all elements.
Added a function to look up all root elements.
Added a function to convert a RELAX NG schema to XML data file.
Added support for XML 1.1 and XHTML 1.0 entities.
Updated the option parser.
Added support for the XML data file header creation.