Mergining libtrianlges

auger() actually builds augers with all params

Added 2D shapes and layout modules

Removed test_libtriangles. I was under the mistaken impression is provided a set of examples, so you could see at a glance the result of the code. This doesn't really need a test function.

radii is used instead of diameters, has a taper parameter that will change how much the blade tapers at the end

clarify that there are no wildcards in OpenSCAD use/include statements