Extracted closestDistance method from closestTrack
Added tracks within range method
getRoutes now uses all tracks close to points

Before getRoutes would only return routes from the closest tracks
to the start and end point
No longer using magic number for getRoutes
Added route length method
Routes from getRoutes is now sorted
Fastest route now uses the first route in routes
Routes vary in intensity when inspecting routes

Faster routes have greater colour saturation
(Fastest route is still gold/yellow)
Added more colour keys
Merge pull request #8 from keemyb/Routing

Routing