* src/gdcmDocEntryArchive.[h|cxx] : bug fix and add a method to temporary

     remove a DocEntry in the header (push an empty DocEntry)
   * src/gdcmFile.[h|cxx] : remove some useless variables, methods and code
     lines. Bug fix in the initialization of the PixelConvert and the
     DocEntryArchive
   * src/gdcmElementSet.[h|cxx] : add methods Initialize and GetNext to
     use in TestCopyDicom (now this test can run under windows... but fails)
   * Test/TestCopyDicom.cxx : amelioration of the test :
     - test the pixels written
     - add test points to quickly find where is the error
     - can set a file name input and output in arguments
   * Test/TestAllReadCompareDicom.cxx, TestReadWriteReadCompare.cxx :
     amelioration of the test output
   * TestCopyDicom always fails... but changes to solve it quickly
   -- BeNours