Default layer offsets to 0, 0 if not present

tests/test_data/layer_tests/all_layer_types/expected.py

@@ -108,6 +108,7 @@ EXPECTED = [
     ),
     layer.ImageLayer(
         name="Image Layer 1",
+        offset=common_types.OrderedPair(1, 4),
         opacity=1,
         visible=True,
         id=3,
@@ -117,6 +118,7 @@ EXPECTED = [
     ),
     layer.ImageLayer(
         name="Image Layer 2",
+        offset=common_types.OrderedPair(0, 0),
         opacity=1,
         visible=True,
         id=5,

tests/test_data/layer_tests/all_layer_types/map.json

@@ -64,6 +64,8 @@
          "id":3,
          "image":"..\/..\/images\/tile_04.png",
          "name":"Image Layer 1",
+         "offsetx":1,
+         "offsety":4,
          "opacity":1,
          "tintcolor":"#ff0000",
          "transparentcolor":"#000000",
@@ -88,7 +90,7 @@
  "nextobjectid":3,
  "orientation":"orthogonal",
  "renderorder":"right-down",
- "tiledversion":"1.6.0",
+ "tiledversion":"1.7.2",
  "tileheight":32,
  "tilesets":[
         {