Extra features and fixes

NaroCAD data model was for sure powerful. It can store almost everything, it propagates data, it is extensible, persistent (can be saved and restored from Xml) and is feature wise a good use of C# 2.0 features as generics constraints, which makes more nice to be used at least than a C++ code.

This means that you can add easy to NaroCAD new extra features as CAM/CAE attributes, constraints, etc.

Sounds great, but his happen to be only on model level. There is always a need to express this at the user level. The most known case is: Property Grid which takes the current shape and gives a custom interface to it. Right now the Property Grid code is refactored to be able to add for any custom attribute a custom Property Grid section.

Right now there is a new section named: Shape that is attached to NamedShape attribute, but it does the job well and proving this concept is working.

Extrude generated using the NewShapeModifer framework is almost working, but I have still to fix bugs to it to behave like the previous code. Like: changing color to red when is live generated, to add second extrude after first one, etc.

Also, I had fixed two bugs: every command line that is executed did not update the view, and there was a case when save/load to XML did not get a reference to the document and make it crash.