- added Features class that describes allowed extension for Reader, to allow for strict configuration
- added tests from json.org jsonchecker and modified jsontestrunner to use strict parsing mode when executing them
diff --git a/include/json/forwards.h b/include/json/forwards.h
index 3372a55..ee76071 100644
--- a/include/json/forwards.h
+++ b/include/json/forwards.h
@@ -9,6 +9,9 @@
    class Reader;
    class StyledWriter;
 
+   // features.h
+   class Features;
+
    // value.h
    class StaticString;
    class Path;