Add explict check for prototype inheritance of entities Chrome bug (see #3973)
Add explict check for prototype inheritance of entities Chrome bug
(see #3973)

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