Cut improvements

Worked at improving Cut algorithm. It works much better, can be applied on the same shape many times without failing. It still has problems if the Cut goes through wires like lines, will have to try to add some wire detection/removal/healing algorithm to cleanup the solid structure.
Also Delete and Box tools were fixed.

Succeeded to draw a simple real model. The drawing process was quite cumbersome. With tasks scheduled for next iterations will boost the usability of the tools, in 2-3 weeks the tools should look much better.

The original shape:



Drawn with Naro:



Cut many times through an extrude: