applied patch from Maurice van der Pot to fix EXSLT week-in-year extenson

* libexslt/date.c tests/exslt/date/datetime.1.out
  tests/exslt/date/date.1.out tests/exslt/date/date.1.xml:
  applied patch from Maurice van der Pot to fix EXSLT
  week-in-year extenson which was not conforming to the definition.
  This also changes the output of the tests a bit. Should fix #452876
Daniel

svn path=/trunk/; revision=1446