Revert "FocusManager::GetNext() selects next visible renderer"
Revert "FocusManager::GetNext() selects next visible renderer"

This reverts commit bb415ef6e788d29de3fd748a95f851fc811bb0c4.

NifTK/MITK,NifTK/MITK,NifTK/MITK,NifTK/MITK,NifTK/MITK,NifTK/MITK