ENH: Updating FindDCMTK.cmake was enough to allow building SPHARM-PDM without Superbuild and with ITK compiled with DCMTK.

See: http://forum.dcmtk.org/viewtopic.php?f=1&t=3906
and: https://github.com/commontk/CTK/commit/15dc10d7cf8e5e30a4e24fbc8eb7b45cd7a3aad3