New Patterns

### 2.6.10 New Patterns

Nine new patterns are added and the crackle pattern has gained four new types. An overview:

- `cells`, fills 3D space with unit cubes. Each cube gets a random value from 0 to 1.
- `crackle`

- `form`
- `metric`
- `offset`
- `solid`

- `facets`, is designed to be used as a normal. This pattern creates facets by snapping normal vectors to the closest vectors in a perturbed grid of normal vectors.
- `fractal`

- The Mandelbrot set with exponents 2 up to 33.
- The equivalent Julia sets.
- The magnet1 and magnet2 fractals

- `function`, use functions to create your own patterns.
- `image_pattern`, instead of placing the color of the image on the object like an `image_map` an `image_pattern` specifies an entire texture item (color, pigment, normal or texture) based on the gray value at that point.
- `object`, generates a pattern based on a pre-declared object.
- `pigment_pattern`, use any pigment as a pattern.
- `slope`. The slope pattern uses the normal of a surface to calculate its slope. It then creates the pattern dependent on the slope and optionally the altitude.
- `function`, takes a "snapshot" of a texture, pattern or function and makes it available as if it where an image. Not a real pattern, but listed here for convenience.