Fix for iOS viewport stretching
Fix for iOS viewport stretching

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