Add labels for vertices (closes #2709)
Add labels for vertices
(closes #2709)

digidem/iD,morray/iD,AndreasHae/iD,1ec5/iD,mapmeld/iD,kartta-labs/iD,1ec5/iD,bagage/iD,bagage/iD,ngageoint/hootenanny-ui,1ec5/iD,morray/iD,ngageoint/hootenanny-ui,AndreasHae/iD,digidem/iD,kartta-labs/iD,AndreasHae/iD,bagage/iD,openstreetmap/iD,openstreetmap/iD,kartta-labs/iD,ngageoint/hootenanny-ui,edpop/iD,edpop/iD,mapmeld/iD,openstreetmap/iD,edpop/iD,mapmeld/iD