[Dcmlib] [CRITICAL] gdcm 12 fixes

[Mathieu Malaterre]

Hi,

  I have commited a couple of fix in the gdcm 1.2 branch. People using
gdcm 1.2 should update to the latest revision of this branch.

1. PrintFile was not catching exception thrown by the gdcm library
thus resulting in application crash
2. gdcmJpeg.cxx was not calling correctly the jpeg lossless function.
Thus producing non-lossless file (result could be up to a +/-1 value
from original pixel value).
3. When DICOM file would contains a UN in a 'well known' DICOM tags,
gdcm would blindly override the value with the -supposively- correct
one. This is incorrect behavior. gdcm is now properly using the
correct VR to read a file.

When rewriting an image, there is still one case not handled. Patch is
in preparation.

Thanks,

-- 
Mathieu