The SWIG wrapper is now functional again, although only a very limited

number of objects are supported so far, to reduce the size of the
wrapper. Details:

* set property eolstyle:native on .cpp and .h files for better windows + linux 
  support

* added small cpp file for quick nif read and write test (for
  debug purposes)

* fixed memory leak due to array of non-fixed sized objects:
  Header.copyright (caused segfaults under GCC)

* disabled pragma warning on NvTriStripObjects.cpp

* fixed undefined behaviour of map[...] = ... map.size() ... in
  niflib.cpp (caused segfaults under GCC)

* cleaned up SConstruct file
  - if DEBUG is false, TUNE is assumed
  - added TEST option

* workaround in pyniflib.h for ReadNifTree (need to find better solution!)

* swig wrapper interface: NiNode, NiAVObject, and NiObjectNET are
  fully supported (nothing else, for now)

* now using unittest for python test script(s)