Lathe updates

Lathe users, here are a couple of new features for you. You can now (in the coming version) mix embedded tools with your own workpieces, materials and zero points. This takes away the need to create your own tools if you can find ones that suits your work among the embedded ones. If not, let us know, we can always add more tool types and geometries in future versions. Another new feature is the possibility to flip the workpiece around in the chuck to machine both sides of it.