title: Parse xsd:dateTime formatted string to python datetime
body: <p>Given a string in <a href="http://books.xmlschemata.org/relaxng/ch19-77049.html" rel="nofollow">xsd:dateTime format</a> I want to create a python datetime object.
  I especially need to be able to parse for example a string like this '2012-09-23T09:55:00', but also all other defined examples should be parsed correctly, and also use timezones.</p>