Cleanup ctkDICOMModel
Cleanup ctkDICOMModel

change bad variable names
convert bitmap role check into real checks
Support more error cases

mehrtash/CTK,lassoan/CTK,vovythevov/CTK,jcfr/CTK,ddao/CTK,pieper/CTK,ddao/CTK,Sardge/CTK,espakm/CTK,rkhlebnikov/CTK,finetjul/CTK,espakm/CTK,danielknorr/CTK,jcfr/CTK,naucoin/CTK,fedorov/CTK,rkhlebnikov/CTK,pieper/CTK,CJGoch/CTK,Sardge/CTK,pieper/CTK,fedorov/CTK,mehrtash/CTK,jcfr/CTK,espakm/CTK,msmolens/CTK,vovythevov/CTK,ddao/CTK,CJGoch/CTK,SINTEFMedtek/CTK,151706061/CTK,naucoin/CTK,finetjul/CTK,CJGoch/CTK,laurennlam/CTK,AndreasFetzer/CTK,SINTEFMedtek/CTK,vovythevov/CTK,jcfr/CTK,finetjul/CTK,ddao/CTK,naucoin/CTK,commontk/CTK,Heather/CTK,danielknorr/CTK,laurennlam/CTK,lassoan/CTK,espakm/CTK,Sardge/CTK,lassoan/CTK,rkhlebnikov/CTK,AndreasFetzer/CTK,AndreasFetzer/CTK,laurennlam/CTK,naucoin/CTK,sankhesh/CTK,CJGoch/CTK,msmolens/CTK,Heather/CTK,SINTEFMedtek/CTK,commontk/CTK,Heather/CTK,finetjul/CTK,mehrtash/CTK,laurennlam/CTK,mehrtash/CTK,SINTEFMedtek/CTK,pieper/CTK,sankhesh/CTK,commontk/CTK,151706061/CTK,151706061/CTK,AndreasFetzer/CTK,rkhlebnikov/CTK,CJGoch/CTK,msmolens/CTK,SINTEFMedtek/CTK,fedorov/CTK,151706061/CTK,sankhesh/CTK,danielknorr/CTK,sankhesh/CTK,151706061/CTK,fedorov/CTK,lassoan/CTK,commontk/CTK,danielknorr/CTK,Heather/CTK,vovythevov/CTK,msmolens/CTK,jcfr/CTK,Sardge/CTK