Customizable coffee mug

=== updated ===
To dive into design with OpenSCAD, I decided to go with a coffee mug, of the cylindrical type. As my first design, it looks pretty good! I am still learning, though. It was made with essentially eight primitives: three toruses and two cylinders, subtracting two cylinders and one torus to make the cavity. My code is a little cluttered, so I will clean it up and perhaps it will render more quickly.

Try setting $fn = 6 and making a hexagonal coffee cup!

Unfortunately, there is a problem with rotation when using odd values for $fn, so stick with even values for now. Also, the handle is a little funky; it might come out offset, and unreasonably thick on smaller cups; I am working to remedy that. For those of you making espresso cups, this will help out a bit. :-)
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Wow, what a response! I got a lot of views, likes, downloads, and customizations on this!
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Update to the file: I gave control of handle minor radius and fixed the problem with cen