Customizable funnel with handle

A parametrizable funnel.
I needed a small one for my own needs, so I share it as it could also be usefull for you.

The OpenSCAD script allows the following parameters:
- Overall thickness (neck tip is thinner than the funnel body and handle).
- Funnel body : height, min and max diameter.
- Funnel neck height and diameter.
- Handle diameter.

The provided STL uses the following parameter values (in mm):
- thickness=1.6; // Overall thickness (neck tip is thinner