Added new method for adding images
Added new method for adding images

mapbox/mapnik-vector-tile,tomhughes/mapnik-vector-tile,mapbox/mapnik-vector-tile,tomhughes/mapnik-vector-tile,mapbox/mapnik-vector-tile,tomhughes/mapnik-vector-tile,tomhughes/mapnik-vector-tile,mapbox/mapnik-vector-tile