Added skeleton of ctkDICOMDisplayedFieldGenerator and a few example rules
Merge remote-tracking branch 'remotes/cpinter-commontk/276-dicom-database-display-tables' into 276-dicom-database-display-tables

Conflicts:
	Libs/DICOM/Core/ctkDICOMDatabase.cpp
	Libs/DICOM/Core/ctkDICOMIndexer.cpp
	Utilities/CMake/FindDCMTK.cmake
Changed display fields map creation for new displayed field generator class

Merge remote-tracking branch 'remotes/lassoan/276-dicom-database-display-tables' into 276-dicom-database-display-tables

Conflicts:
	Libs/DICOM/Core/ctkDICOMDatabase.cpp