Added Extrude and Fillet operations to the Ocaf data tree. It works properly to Undo/Redo the operations on the data structure. Moved the code for these operations to the OcafDirvers package.
Remained to implement the Cut feature with Ocaf. This looks a little more complex because at the current implementation the Cut is made through all the shapes, theoretically it may modify all the data from the data tree not only one shape as it happened until now for the other operations.
The source code is not yet uploaded on SVN because the Cut feature on visual objects doesn't work properly together with the two other features implemented with Ocaf.