* Adaptation for porting to VC++:

  * Adaptation for porting to VC++:
        - src/gdcm.h
          o forced to use std namespace (for string to be known)
          o all class use __declspec export style on WIN32
        - src/gdcmUtil.cxx new Exit method that wraps the exit call
          (in stdlib.h on Win32 but in std:: for gcc)
      * src/gdcmDictSet::SetDictPath adds a trailing / to environement
        variable GDCM_DICT_PATH.
      * src/gdcmHeader.cxx verbose comments made discrete. --- Frog