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/model/ccnx-fib.h b/model/ccnx-fib.h
index e5bda1e..eae0c65 100644
--- a/model/ccnx-fib.h
+++ b/model/ccnx-fib.h
@@ -132,6 +132,12 @@
   Print (std::ostream &os) const = 0;
 
   /**
+   * @brief Get number of entries in FIB
+   */
+  virtual uint32_t
+  GetSize () const = 0;
+
+  /**
    * @brief Return first element of FIB (no order guaranteed)
    */
   virtual Ptr<const CcnxFibEntry>