Draft BSpline

Description
This tool asks the user for several points and draws a B-Spline passing through them. The newly created wire will have the current color and width. The points can be picked with the mouse in the 3d view or by entering coordinates with the keyboard.

Usage

 * Picking a point on an empty area of the 3d view, or on an existing object.
 * Pressing will snap your point to available snap locations.
 * Pressing will constrain your new point in relation to the last one.
 * Enter numbers to manually insert a coordinate.
 * Pressing + or pressing the "Undo" button will undo the last point.
 * Pressing will cancel the operation.
 * The newly created spline will take the current linestyle.
 * Double-clicking the last point, instead of simply clicking, will finish and close the spline.
 * Pressing or context menu > draft > Finish or pressing the "Finish" button will also finish the spline, leaving it open.
 * -Clicking (snapping) on the first point will finish and close the spline
 * Pressing or context menu > draft > Close or pressing the "Close" button will also finish and close the spline.
 * Closing/opening the wire can also be done via its properties.
 * An open spline can have a dimension symbol displayed at its endpoint, so it can be used as a leader.