Store Python objects to (pickle-like) XML Documents

Note 0:

    See [...]/gnosis/doc/xml_matters_1.txt for a detailed
    discussion of this module.  An updated discussion of changes
    in the module is at [...]/gnosis/doc/xml_matters_11.txt.
    These articles may also be found (with pretty formatting) at
    <http://gnosis.cx/publish/>.

    Some enhancements have been contributed by various users,
    please see [...]/gnosis/xml/pickle/doc/HISTORY for details.
    Some enhancements may go beyond what is discussed in the
    referenced article.

Usage:

    xml_pickle offers quite a few ways to perform pickling, so
    you can pick and choose at your convenience.

      # By inheritence
      from gnosis.xml.pickle import XML_Pickler
      class MyClass(XML_Pickler):
      # create some behavior and attributes for MyClass...
      o1 = MyClass()
      # o1 knows how to dump itself
      xml_str = o1.dumps()
      o2 = o1.loads(xml_str)

      # With inline instantiation
      # NOTE: some borderline cases, like builtin types, are
      #       incompatible with this style (use below style)
      from gnosis.xml.pickle import XML_Pickler
      o1 = DataClass()
      # ...assign attribute values to o1...
      o1 = XML_Pickler(o1)
      # this o1 also knows how to dump itself
      xml_str = o1.dumps()
      o2 = XML_Pickler().loads(xml_str)

      # Another way to do inline instantiation
      from gnosis.xml.pickle import XML_Pickler
      o1 = DataClass()
      # ...assign attribute values to o1...
      xml_str = XML_Pickler().dumps(o1)
      o2 = XML_Pickler().loads(xml_str)

      # Or, inline, the way pickle does it
      import gnosis.xml.pickle
      xml_str = gnosis.xml.pickle.dumps(obj)
      o2 = gnosis.xml.pickle.loads(xml_str)

Security:

    The file [...]/gnosis/xml/pickle/doc/SECURITY contains
    details of the [xml_pickle] security model and options.  For
    the impatient, the following code will give decent security
    with the "expected" pickle behavior:

       from gnosis.xml.pickle import setParanoia
       setParanoia(0)

Compatibility:

    Requires Python 2.0 and up, however, the PyXML package
    included in Python 2.0 is too old.  You'll have to install a
    newer version (at least 0.6.1) from:

      http://pyxml.sourceforge.net/topics/download.html