Sketching improvement

In the last days worked at improving the sketching capabilities of NaroCad and the basic drawing concepts.
Mainly the Face will be the basic unit of drawing. An example on how this will affect the application: the rectangle tool will generate a wire that will be attached to a MakeFace function. In the tree view a Face node will appear having as child node a rectangle (all changes to the wire propagate and the Face is regenerated). On the Face can be applied a tool like Extrude. All the basic shapes will be built on this concept. The 2D tools will be adapted to work with these structures: the Fillet 2D will know how to modify the wire that generated the Face, will add a tool to add and remove wires from an existing Face. These will work together with the automatic face detector that searches for closed wires and generates Faces from them. Also grouping and ungrouping them will be easy.

This working style started to look like the Sketch concept found at the majority of modeling applications: every 2D drawing is found in the 3D space as a Sketch on which the Features can be applied.