Iteration 0.0.10

The tasks proposed for the Iteration 0.0.10 that will close on May 10:

- review the code written at the Data Tree and at the 3D drawing,estimated to take 2-3 hours (task already finished),
- make the Extrude work (some of the subtasks: improve the face picker, the drawn Extrude disappears - needs to be solved, make the Extrude work with clicks instead of drags, Extrude remains active when changing to another tool, enable extruding the face of an extrude, don't register the intermediary Extrude shapes in the Data Tree until it is finished), task estimated to take 3-4 days of work,
- make the Fillet work (Fillet should be drawn using a fixed radius that will be changed from the Property dialog, solve the Fillet bugs from the Property dialog), task estimated to take 2 days,
- cancel the current selected action and switch to ActionNone using the Cancel button, estimated to take 0.5 hours,
- Implement test codes at the Sketcher (make tests for 2D shapes, test 2D drawing, try to test the edit mode), task estimated to take 6 hours,
- Add functionality to draw a 2d rectangle in the 3d space, estimated to take 1 day.