This unifies deletion behavior for all PartDesign features ensuring that
sketches that were used to create these features show after deletion and
that the tip is properly transfered.
These features, based on the code for the Pipe class, allow the user
to simply create a helical sweep within PartDesign workbench.
Sample application is threads, springs, coils, augers, etc.
Also, remove needless requirement for positive cone angle on helixes.
Thanks to @bitacovir for helping with the icons
Thanks to @chennes for review
Thanks to @vosk for review
Thanks to @wwmayer for review
Enforce that links stay within scope for ProfileBased features
This also ensures that the Body itself is not used for creating features within
the body, causing a "Graph not a DAG" error.
