Return shallow clones of features, because the hashes may change
Return shallow clones of features, because the hashes may change

If we return the original feature, and then change the hash later as the
feature merges with another, d3 won't exit/enter because it is joining
on the new hash, not the originally hash.

openstreetmap/iD,AndreasHae/iD,openstreetmap/iD,ngageoint/hootenanny-ui,openstreetmap/iD,morray/iD,AndreasHae/iD,kartta-labs/iD,digidem/iD,ngageoint/hootenanny-ui,kartta-labs/iD,kartta-labs/iD,digidem/iD,morray/iD,ngageoint/hootenanny-ui,AndreasHae/iD