1) The update areas are now split into 512x512px patches
2) The update "queue" now works like a "stack" =) It means that it
   will first update area, where the user is painting *right now*. If
   the updater have missed some areas, they will be postponed until
   better days, because more recent areas have higher priority.

svn path=/trunk/koffice/; revision=1149823