Odd drawing mode

[Inglonias]

It would be useful for certain tools to be able to draw in an "odd" fashion. For example, a circle with a radius of 1.5 rather than 1, 2.5 rather than 2, and so on.

While I haven't worked out the math yet, I have an idea for an implementation style - Everything that implements IDrawTool must provide a DrawWithToolOdd method that returns a LineSegment[]. The default implementation of this would be to just call DrawWithTool as normal, but for tools where it matters, there can be a different implementation.