Introducing a couple of real test cases.

Also, basic PIT test shows that everything works as expected...

There was one big change in PIT. Previously, when PIT entry was
satisfied, it was immediately removed. As of recently, PIT entry is
immediately removed.
diff --git a/test/ndnSIM-pit.h b/test/ndnSIM-pit.h
new file mode 100644
index 0000000..3bc1705
--- /dev/null
+++ b/test/ndnSIM-pit.h
@@ -0,0 +1,53 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef NDNSIM_TEST_PIT_H
+#define NDNSIM_TEST_PIT_H
+
+#include "ns3/test.h"
+#include "ns3/ptr.h"
+
+namespace ns3
+{
+
+class CcnxFib;
+class CcnxPit;
+  
+class PitTest : public TestCase
+{
+public:
+  PitTest ()
+    : TestCase ("PIT test")
+  {
+  }
+    
+private:
+  virtual void DoRun ();
+
+  void Test (Ptr<CcnxFib> fib);
+  void Check0 (Ptr<CcnxPit> pit);
+  void Check1 (Ptr<CcnxPit> pit);
+  void Check2 (Ptr<CcnxPit> pit);
+  void Check3 (Ptr<CcnxPit> pit);
+};
+  
+}
+
+#endif // NDNSIM_TEST_PIT_H