Line parallel with plane

The Extrude meta tool is finalized and activated in Naro; it has the same functionality as previously.

Finalized a first version of line parallel with plane tool. It needs some bug fixing before activation in Naro. While working at this tool found improvements and fixes at the Meta Tools base classes. Also extended the Line Function class (the class that knows how to generate OpenCascade lines); the class can take two extra arguments that specify the type of line generated and a reference (ex: type is "parallel line" that has a reference to a plane to which it is parallel to). This extension will make easier to implement also the line normal to a surface tool.
Hoping in half of day to finish both these tools then will continue with the 3D shapes like cone, box, etc that are estimated to take around 2-3 days to finish.

The hints added at the line, rectangle, circle and boolean tools seem to work well. They are also useful as helpers for the user to know what's the next action to do.

Currently the work is on schedule for the 1.4 Beta planned for the end of the week (on Friday evening or Saturday).