Implementing notion of default routes (useful for Flooding scenarios)

Also, correcting SEGFAULT upon termination (when apps was destroyed
after ccnx stack)

Correcting LongestPrefixMatch to be able to perform default match
diff --git a/apps/ccnx-app.cc b/apps/ccnx-app.cc
index 7b9c2b9..afdf9de 100644
--- a/apps/ccnx-app.cc
+++ b/apps/ccnx-app.cc
@@ -55,7 +55,6 @@
     
 CcnxApp::~CcnxApp ()
 {
-  StopApplication ();
 }
 
 void
@@ -63,7 +62,9 @@
 {
   NS_LOG_FUNCTION_NOARGS ();
 
-  StopApplication ();
+  // Unfortunately, this causes SEGFAULT
+  // The best reason I see is that apps are freed after ccnx stack is removed
+  // StopApplication ();  
   Application::DoDispose ();
 }