* src/gdcm.h and gdcmHeader.cxx gdcm no longer loads all the elements

  * src/gdcm.h and gdcmHeader.cxx gdcm no longer loads all the elements
        values, but limits itself to values which are below a user specified
        size (by default 1024 bytes).
      * python/gdcm.i : elements not loaded (because their size is above the
        user specified treshold) are exported with their TagKey as key of the
        python dictionary. This enables the testsuite to make some checks
        on the unloaded elements (since we have their offset and size).
      * python/testSuite.py
        - now tests for the existence and proper value of the pixel data
        - two new examples added.
      * Data/gdcm-MR-SIEMENS-16.acr[12] added.   --- Frog