incorrect warning

[dieterdreist]

I got a warning about "overlapping landuse" when actually I had 2 landuse polygons sharing 1 way (via Multipolygon). There is no issue with such mapping, rather people should be encouraged to keep landuse polygons small, because it makes maintenance easier and makes it easier to refine the polygons with additional properties. If we encourage people to merge landuse polygons because they are of the same type and touching, we will loose way history (not really "lost", but becomes unaccessible during regular editing), and make it harder to add more detail (because these polygons will have to be split again).