Change to 80px arrow key panning (this matches Leaflet default) (closes #4207)
Change to 80px arrow key panning (this matches Leaflet default)
(closes #4207)

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