* Doc/Doxyfile configuration file for Doxygen and corresponding

  * Doc/Doxyfile configuration file for Doxygen and corresponding
        README file for usage added.
      * Test/testWrite.cxx added. This new test comes from a split of
        test.cxx that is now reverted to its original purpous i.e.
        testing the proper parsing of a Dicom related file.
        testWrite.cxx concentrates on testing the IO part of gdcm.
      * Test/bug1.cxx (containing a bug on WIn32) added.
      * src/gdcm.h, gdcmHeader.cxx, gdcmDictSet.cxx:
        - gdcmHeader::GetPubTagNames and  gdcmHeader::GetPubTagNamesByCategory
          whose purpose is to publish the content of the TagNames of the
          Dicom public dictionnary were not accessible without an
          instance of class gdcmHeader.
        - those methods are now static methods of gdcmDictSet and hence
          require no instances at all to be invocated.
        - within gdcmDictSet this change required to change some method
          to class methods (i.e. are now static) among which SetDictPath
          (renamed to BuildDictPath) and LoadDefaultPubDict.
      * python/gdcmPython/demo/printGroupedPublicDict.py changed to illustrate
        the above changes by calling the new method classes of gdcmDictSet.
      * python/gdcmPython/__init__.py now exposes gdcm.gdcmDictSet for
        the above to be effective.
      * python/gdcmPython: in order to wrap properly the above changes
        for Python, swig version now needs to be > 1.3.17.
      * python/gdcmPython/Makefile fixed to adapt itself to new
        configure/make shema introduced by Johan Montagnat (thanks for the
        contribution). Alas this Makefile cannot be turned into a proper
        Makefile.am without some heavy changes in the configure.in
        (for python dectection).
      * python/gdcmPython/gdcm.i: the out typemap map<string, list<string>>*
        now avoids publishing the empty entries.   --- Frog