saves map on change zoom, refs #1862
saves map on change zoom, refs #1862

CartoDB/cartodb,DigitalCoder/cartodb,UCL-ShippingGroup/cartodb-1,nuxcode/cartodb,future-analytics/cartodb,bloomberg/cartodb,splashblot/dronedb,bloomberg/cartodb,raquel-ucl/cartodb,codeandtheory/cartodb,codeandtheory/cartodb,thorncp/cartodb,dbirchak/cartodb,codeandtheory/cartodb,CartoDB/cartodb,bloomberg/cartodb,UCL-ShippingGroup/cartodb-1,thorncp/cartodb,splashblot/dronedb,bloomberg/cartodb,codeandtheory/cartodb,splashblot/dronedb,splashblot/dronedb,dbirchak/cartodb,nyimbi/cartodb,future-analytics/cartodb,nuxcode/cartodb,nuxcode/cartodb,raquel-ucl/cartodb,nyimbi/cartodb,nyimbi/cartodb,dbirchak/cartodb,codeandtheory/cartodb,CartoDB/cartodb,DigitalCoder/cartodb,UCL-ShippingGroup/cartodb-1,thorncp/cartodb,CartoDB/cartodb,UCL-ShippingGroup/cartodb-1,thorncp/cartodb,future-analytics/cartodb,dbirchak/cartodb,nyimbi/cartodb,future-analytics/cartodb,raquel-ucl/cartodb,dbirchak/cartodb,UCL-ShippingGroup/cartodb-1,nuxcode/cartodb,CartoDB/cartodb,thorncp/cartodb,raquel-ucl/cartodb,future-analytics/cartodb,DigitalCoder/cartodb,DigitalCoder/cartodb,DigitalCoder/cartodb,raquel-ucl/cartodb,splashblot/dronedb,nyimbi/cartodb,nuxcode/cartodb,bloomberg/cartodb