Update d3.d.ts to include x,y on stack layout
Update d3.d.ts to include x,y on stack layout

softwords/plottable,NextTuesday/plottable,iobeam/plottable,RobertoMalatesta/plottable,palantir/plottable,gdseller/plottable,danmane/plottable,alyssaq/plottable,NextTuesday/plottable,jacqt/plottable,palantir/plottable,softwords/plottable,jacqt/plottable,onaio/plottable,onaio/plottable,NextTuesday/plottable,RobertoMalatesta/plottable,softwords/plottable,alyssaq/plottable,danmane/plottable,palantir/plottable,palantir/plottable,onaio/plottable,jacqt/plottable,gdseller/plottable,iobeam/plottable,gdseller/plottable,alyssaq/plottable,iobeam/plottable,RobertoMalatesta/plottable,danmane/plottable