Updating areas already imported with the new building data from LA County

[maning]

For discussion here how do we update OSM with the latest building data from LA County.

For context, our previous import were based on the 2008 LA building data, the recent release from LA County GIS includes changes from 2008-2014. We already imported ~2M buildings based on the 2008 dataset. Local mappers have already started improving the imported data. We need to ensure that local improvements won't be damaged if we intend to refresh.

[maning]

Related ticket: https://github.com/osmlab/labuildings/issues/6

[AshotN]

Are building numbers going to be imported this time?