[Dcmlib] GDCM 1.2.5 update

[Mathieu Malaterre]

This new release fix the followings:

* MAJOR: Add VR: OF
* MAJOR: 16Bits JPEG stored in 12Bits DICOM would be truncated to
12Bits value resulting in loss of details.
* MINOR: Fix mem leak in gdcmElementSet.cxx
* MINOR: Fix bad pointer access when missing info in CheckMandatoryElements()
* MINOR: Handle SIEMENS file with palette AND PhotometricInter sets to
MONOCHROME2

Ref:
http://sourceforge.net/project/showfiles.php?group_id=137895&package_id=151454&release_id=646573

Enjoy.

-- 
Mathieu