FIX (#1575): Material editor crashes on closing
FIX (#1575): Material editor crashes on closing

Changed node traversal from data tree traversal to data storage traversal. This somehow fixes the problem.




lsanzdiaz/MITK-BiiG,nocnokneo/MITK,NifTK/MITK,rfloca/MITK,RabadanLab/MITKats,NifTK/MITK,iwegner/MITK,NifTK/MITK,fmilano/mitk,NifTK/MITK,MITK/MITK,MITK/MITK,danielknorr/MITK,fmilano/mitk,MITK/MITK,fmilano/mitk,nocnokneo/MITK,fmilano/mitk,nocnokneo/MITK,rfloca/MITK,iwegner/MITK,NifTK/MITK,rfloca/MITK,RabadanLab/MITKats,fmilano/mitk,nocnokneo/MITK,MITK/MITK,iwegner/MITK,MITK/MITK,lsanzdiaz/MITK-BiiG,danielknorr/MITK,danielknorr/MITK,rfloca/MITK,nocnokneo/MITK,fmilano/mitk,lsanzdiaz/MITK-BiiG,lsanzdiaz/MITK-BiiG,iwegner/MITK,RabadanLab/MITKats,iwegner/MITK,lsanzdiaz/MITK-BiiG,danielknorr/MITK,MITK/MITK,nocnokneo/MITK,rfloca/MITK,rfloca/MITK,fmilano/mitk,rfloca/MITK,danielknorr/MITK,danielknorr/MITK,RabadanLab/MITKats,lsanzdiaz/MITK-BiiG,iwegner/MITK,RabadanLab/MITKats,danielknorr/MITK,lsanzdiaz/MITK-BiiG,RabadanLab/MITKats,nocnokneo/MITK,NifTK/MITK,lsanzdiaz/MITK-BiiG