working on voronoi/delaunay
added memoryleak :(
big refactoring, getting rid of DistrictParcel
got rid of districtParcel, added DB, nothing works :)
shifted Grid > UrbanGrid
database is working now, note: @Id MUST be 'Integer'
cleanup, prevent NPE
 prevent some more NPE, still not stable
fixed much, streets now work correctly and get pasted. Other schems still missing.
seems stable, cache no longer fully flushes
fixed missing height estimator
cleanup, optimised imports
rearrangement of packages
abstracted districs