* organized nifxml python code as a python library in a directory,

  still need to make seperate files for seperate parts of the library

* (!!!) moved nif.xml and kfm.xml file to reflect the reorganization;
  I tried to fix references to it in all other projects

* niflib now imports nifxml code through svn:externals (as svn
  symbolic links are not supported under windows)

* scons generates list of header files via nifxml library: no longer
  need to manually update the list

* SConstruct generator removed from nifxml_niflib.py script as scons
  now uses the nifxml library directly

* fixed typo in nif.xml

* property svn:eol-style set to native on some files