Initial import of py-elementtree, from pkgsrc-wip, packaged by recht@

Initial import of py-elementtree, from pkgsrc-wip, packaged by recht@

The Element type is a simple but flexible container object, designed
to store hierarchical data structures, such as simplified XML infosets,
in memory.

The ElementTree toolkit contains an Element implementation in Python,
and code to read XML and HTML files into trees of Element objects, and
write them out as XML.