ENH: add more DCMTK applications
Created by: fedorov
Applications added:
- dcm2xml: convert DICOM into XML representation (http://support.dcmtk.org/docs/dcm2xml.html)
- dsr2xml: convert SR DICOM into XML representation (http://support.dcmtk.org/docs/dsr2xml.html
- dsrdump: SR-specific version of dcmdump already included (http://support.dcmtk.org/docs/dsrdump.html)