fix syntax errors, logic errors, add logging to find errors, test that it works

lib/tilesheet.lua

@@ -18,7 +18,7 @@ local tile_metatable = {
   }
 }
 
-local tilesheet.load = function(data_or_path)
+tilesheet.load = function(data_or_path)
   local tile_image, tile_size
   local tiles = {}