Test runner: Detect extra property in 'actual' but not in 'expected'. (#407)

* Test runner: Detect extra property in 'actual' but not in 'expected'.

Also update all expected.json where this would result in errors.

* Include rmExpected.js script in case it is needed again

test/fixtures/es2015/modules/export-default-function-declaration-expression-disambiguation/expected.json

@@ -59,6 +59,7 @@
           "id": null,
           "generator": false,
           "expression": false,
+          "async": false,
           "params": [],
           "body": {
             "type": "BlockStatement",
@@ -105,11 +106,13 @@
             "end": {
               "line": 2,
               "column": 4
-            }
+            },
+            "identifierName": "foo"
           },
           "name": "foo",
           "extra": {
-            "parenthesized": true
+            "parenthesized": true,
+            "parenStart": 30
           }
         }
       }