Fix column names extractor SQL. Closes #895
Fix column names extractor SQL. Closes #895

Conflicts:
	app/models/table.rb

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