This patch does at least one global change:

1) Now KisNodeModel has *two* columns! The first one is purely technical
   and does nothing. It is only needed to reserve space for the visibility
   icon that is painted over it by KisNodeDelegate attached to the second
   column. See comments in
      o KisNodeModel::columnCount()
      o KisNodeDelegate::editorEvent()
      o KisNodeDelegate::drawVisibilityIconHijack()

Ref T106,M11