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/estree/object-property/basic/expected.json

@@ -150,4 +150,4 @@
       }
     ]
   }
-}
+}