Update to D3 2.9.1.
Update to D3 2.9.1.

fbukevin/weic_d3js,ImFreeApp/resource-stack,SoxFace/stack,Archie22is/stack,bondah/GIS_Intro,ee08b397/stack,banj/stack,Archie22is/stack,ee08b397/stack,atogle/presentations,banj/stack,bondah/GIS_Intro,fbukevin/weic_d3js,ImFreeApp/resource-stack,SoxFace/stack,mbostock/stack,tailhook/leap_presentation,mbostock/stack,gideonite/WIP