improve tennis icon for MapView, new icons for canoe (http://osm-icons.org/wiki/File:21097.svg, modified, CC0), and miniature_golf (http://osm-icons.org/wiki/File:21019.svg, modified, CC0)

git-svn-id: http://svn.openstreetmap.org/applications/share/map-icons@30798 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4