Parametric Tube Adapter

Useful for vacuum dust systems or any need where two tubes of differing diameters need to be joined (or just as a funnel).
I updated the OpenSCAD script to correctly reflect the ID of both the top and bottom (it had previously been using the input ID as radius, not diameter). Also added an Echo function to display the total height of the Adapter. A Diagonal angle calculator is in the pipeline (if you'll excuse the pun), designed to throw a warning if the angle is too low to print.