Several fixes in forwarding strategies and NACK processing

- All strategies will forward to one green face first, if it exists
- Implemented logic to detect retransmitted interests (same face)
- If interest is retransmitted and all faces are exhausted during the
  propagation face, increase max retx counter and try again
- PIT entry lifetime is updated on every non-duplicate interest reception
diff --git a/model/ccnx-pit-entry-outgoing-face.h b/model/ccnx-pit-entry-outgoing-face.h
index 0fce545..c0fe80f 100644
--- a/model/ccnx-pit-entry-outgoing-face.h
+++ b/model/ccnx-pit-entry-outgoing-face.h
@@ -38,14 +38,18 @@
   Time m_sendTime;          ///< \brief time when the first outgoing interest is sent (for RTT measurements)
                             ///< \todo handle problem of retransmitted interests... Probably, we should include something similar
                             ///<       to TimeStamp TCP option for retransmitted (i.e., only lost interests will suffer)
-  // uint32_t m_retxNum;       ///< \brief number of retransmission
-  // int m_nonce;              ///< \brief nonce of the outgoing Interest
-  // bool m_outstanding;		///< \brief flag to indicate that this interest is currently pending
+  uint32_t m_retxCount;     ///< \brief number of retransmission
   bool m_waitingInVain;     ///< \brief when flag is set, we do not expect data for this interest, only a small hope that it will happen
 	
 public:
   CcnxPitEntryOutgoingFace (Ptr<CcnxFace> face);
 
+  /**
+   * @brief Update outgoing entry upon retransmission
+   */
+  void
+  UpdateOnRetransmit ();
+
   bool operator== (const CcnxPitEntryOutgoingFace &dst) { return *m_face==*dst.m_face; }
   bool operator== (Ptr<CcnxFace> face) { return *m_face==*face; }