ForwardingFlags: Added ForwardingFlags class and use it in registerPrefix and ForwardingEntry instead of int flags.
diff --git a/ndn-cpp/face.hpp b/ndn-cpp/face.hpp
index f20bc26..c3ced09 100644
--- a/ndn-cpp/face.hpp
+++ b/ndn-cpp/face.hpp
@@ -87,12 +87,13 @@
    * use func_lib::ref() as appropriate.
    * @param onRegisterFailed A function object to call if failed to retrieve the connected hub’s ID or failed to register the prefix.
    * This calls onRegisterFailed(prefix) where prefix is the prefix given to registerPrefix.
-   * @param flags The flags for finer control of which interests are forward to the application.  If omitted, use 3 (ACTIVE | CHILD_INHERIT).
+   * @param flags The flags for finer control of which interests are forward to the application.  If omitted, use 
+   * the default flags defined by the default ForwardingFlags constructor.
    * @param wireFormat A WireFormat object used to encode the input. If omitted, use WireFormat getDefaultWireFormat().
    */
   void 
   registerPrefix
-    (const Name& prefix, const OnInterest& onInterest, const OnRegisterFailed& onRegisterFailed, int flags = 3, 
+    (const Name& prefix, const OnInterest& onInterest, const OnRegisterFailed& onRegisterFailed, const ForwardingFlags& flags = ForwardingFlags(), 
      WireFormat& wireFormat = *WireFormat::getDefaultWireFormat())
   {
     node_.registerPrefix(prefix, onInterest, onRegisterFailed, flags, wireFormat);