apply suggested fix for #3

Helpers.jrag

@@ -56,8 +56,14 @@ aspect Helpers {
 
   // --- helper methods for put/add ---
   protected SimpleElement ComplexElement.makeStringElement(String value) {
+    if (value == null || value.equals("null")) {
+      return StringElement.of("null");
+    }
+    if (value.isBlank()) {
+      return StringElement.of(value);
+    }
     // simple test, check for special characters
-    return containsAny(value, "[{\"\n") ?
+    return containsAny(value, ":#,[{\"\n") ?
       StringElement.of(value.replace("\n", "\\n").replace("\"", "\\\"")) :
       ValueElement.of(value);
   }