Geometric fill/outline tools

[Flashing-Blinkenlights]

Feature branch: geometry It would be nice to have a selection of functions to draw a variety of geometric shapes efficiently, both filled and hollow. Some ideas for useful shapes:

• [x] Cuboids
• [x] Point-to-point shapes / polygons
• [x] Circles, ellipses and cylinders
• [ ] Ellipsoids
• [ ] Arches
• [x] Repeated shapes
• [x] Transformed shapes
• [ ] Rotated shapes

Suggested implementation:

Using various combinations of Bresenham's algorithms

[Flashing-Blinkenlights]

It would likely make sense to do this in a new module and have the fill command move there.

[avdstaaij]

Moved to https://github.com/avdstaaij/gdpc/issues/25