Changed many functions to speak RGBA instead of PIL.Image so there would be fewer img2arr/arr2img conversions
Changed many functions to speak RGBA instead of PIL.Image so there would be fewer img2arr/arr2img conversions

moskvax/TileStache,SEL-Columbia/TileStache,MetGIS/TileStache,Billups/TileStache,mapzen/TileStache,moskvax/TileStache,mojodna/TileStache,Kosta-Github/TileStache,Billups/TileStache,TileStache/TileStache,jbants/TileStache,mapzen/TileStache,SEL-Columbia/TileStache,jbants/TileStache,Blechhirn/TileStache,mpuig/TileStache,mpuig/TileStache,MetGIS/TileStache,TileStache/TileStache,jbants/TileStache,Blechhirn/TileStache,Blechhirn/TileStache,SEL-Columbia/TileStache,TileStache/TileStache,Billups/TileStache,mojodna/TileStache,Kosta-Github/TileStache,robpvn/Vector-Tile-Research,Kosta-Github/TileStache,robpvn/Vector-Tile-Research,mapzen/TileStache,robpvn/Vector-Tile-Research,MetGIS/TileStache,moskvax/TileStache