minor refactoring for calculating distances
added concentric coloring
I really need to stop committing debug code
changed distance implementation again
renamed the starting point for concentric coloring so it's clear that it doesn't need to start in the center'
separated out method to find closest SeedNode to a given Location
no longer 'theoretical' hexagons
Merge pull request #5 from adamreis/adam_add_concentric_coloring

Added concentric coloring
fix merge conflict