ENH: Updated SlicerRT: Fixing nightly builds issue due to DCMTK changes (other improvements are also included, but they are going to be released officially in an upcoming version). See more info at https://www.assembla.com/code/slicerrt/subversion/changesets/compare/519..572
Merge pull request #170 from SlicerRt/update-SlicerRT

ENH: Updated SlicerRT: Fixing nightly builds issue due to DCMTK changes ...