* tree.c: hardened the addChild function
* python/generator.py python/libxml.c python/libxml2-python-api.xml
  python/libxml2class.txt python/libxml_wrap.h python/TODO:
  added accessors needed for xmlNode, a bit more testing and
  extension of interfaces
* python/tests/Makefile.am python/tests/build.py: added a test
  build from scratch/save/load/check
Daniel