XML::LibXML direct SAX parser

Description
XML::LibXML provides an interface to libxml2 direct SAX interface. Through this interface it is possible to generate SAX events directly while parsing a document. While using the SAX parser XML::LibXML will not create a DOM Document tree.
Such an interface is useful if very large XML documents have to be processed and no DOM functions are required. By using this interface it is possible to read data stored within a XML document directly into the application data structures without loading the document into memory.
The SAX interface of XML::LibXML is based on the famous XML::SAX interface. It uses the generic interface as provided by XML::SAX::Base.
Additionally to the generic functions, which are only able to process entire documents, XML::LibXML::SAX provides parse_chunk(). This method generates SAX events from well balanced data such as is often provided by databases.
NOTE: At the moment XML::LibXML provides only an incomplete interface to libxml2's native SAX implementation. The current implementation is not tested in production environment. It may causes significant memory problems or shows wrong behaviour. If you run into specific problems using this part of XML::LibXML, let me know.