* Draft wire points can be dragged individually.
* Draft wire individual edge can be moved and rotated.
* Draft circle/arc can be moved and rotated by dragging edge or face.
* Draft circle/arc radius can be changed by dragging vertex
* Draft arc first/last angle can be changed by dragging end points
When added to an assembly, a normal part object has six degrees of
freedom, three positional and three rotational. A draft circle has one
additional dof, its radius. And a draft arc has three additional dof,
radius, first angle and last angle.
Special treatment for non-closed-or-subdivided draft wire object
directly added into part group. Instead of constraining on the object
placement, we shall constraint on individual points. In other word,
instead of making the draft wire's placement as free parameters, we
make the cooridnates of indvidual points as free parameters.
Working constraints:
PointPlaneDistance
PointInPlane
Angle
Perpendicular
Parallel
New constraints, which are composite of slvs native constraints:
PlaneCoincident
PlaneAlignment
AxialAlignment
MultiParallel
