Make perspective scale work more explicitly from properties

assets/imagemap.tmj

@@ -30,7 +30,7 @@
                          "name":"character",
                          "type":"string",
                          "value":"little guy"
-                        }, 
+                        },
                         {
                          "name":"state",
                          "type":"int",
@@ -40,8 +40,8 @@
                  "type":"actor",
                  "visible":true,
                  "width":16,
-                 "x":440.510088317656,
-                 "y":140.347239175702
+                 "x":140.510088317656,
+                 "y":400.347239175702
                 }, 
                 {
                  "gid":149,
@@ -72,17 +72,29 @@
                  "name":"p_foreground",
                  "rotation":0,
                  "type":"perspective",
+		 "properties": [
+			{
+			  "name": "scale",
+			  "type": "number",
+			  "value": 1.5
+			}],
                  "visible":true,
                  "width":790,
                  "x":0,
                  "y":410
                 }, 
                 {
-                 "height":16,
+                 "height":12,
                  "id":17,
                  "name":"p_vanishing",
                  "rotation":0,
                  "type":"perspective",
+		 "properties": [
+			{
+			  "name": "scale",
+			  "type": "number",
+			  "value": 0.75
+			}],
                  "visible":true,
                  "width":53,
                  "x":270.5,