Volume calculation

 From:  Max Smirnov (SMIRNOV)
I think there is no need to write a script for exact calculation of volume.
99% accuracy should be enough. I can write such a script very easily.
I have checked two methods today, but I found that some moi functions doesn't work as I need.

Here is the issues:
1. Boolean Isect doesn't work with solid and line.
2. Curve Isect generates many wrong points of intersections in some cases.

The last way which I can use is Trim function.. I'll check it.