Algorithm optimisation and Architecture/Maintainability

[Harmos274]

Slow algorithm.

Should improve performances of assignCluster, need to remove the sortOn which is unnecessary complex.

Should rework the module organisation in files, use ImageDefinition as a directory and fill it with Color, Pixel, Position, Cluster.

[Harmos274]

Despite what i wrote sortOn seems to be a very well optimized function due to
Schwartzian transform.