BUG: Widgets/ctkTransferFunctionItem - Fix warning and added separator comment between function
BUG: Widgets/ctkTransferFunctionItem - Fix warning and added separator comment between function

The following warning has been fixed:
warning C4099: 'ctkControlPoint' : type name first seen using 'struct' now seen using 'class'

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