Fix star visilibity and documentation (since 946c03c6)

Fix memory leak (unused allocation)
Fix star rendering
Rename sky color struct
Fix stars on android
Remove extraneous .data() from android star draw

src/script/lua_api/l_object.cpp

@@ -2059,7 +2059,7 @@ int ObjectRef::l_set_stars(lua_State *L)
 	lua_pop(L, 1);
 
 	star_params.scale = getfloatfield_default(L, 2,
-		"size", star_params.scale);
+		"scale", star_params.scale);
 
 	getServer(L)->setStars(player, star_params);
 	lua_pushboolean(L, true);