Tubing Library

I'd really like the ability to save tubes for use in other frames - this would be useful for the stranger shaped main tubes, but really really useful for stays.

I've written up some of my ideas about it: https://docs.google.com/document/d/17hVAD_Uz9grVpcRsr3_VgWFW29UVdVH8RwiwTpPplv0/

The basic idea is that I could define the geometry of a tube, give it a name (I'd use the part number I get from Framebuilder Supply), then I could re-use that tube in future builds.

Thanks so much!

Justin