face: Implementing new "isOnDemand" flag

This flags replaces isPermanent flag in datagram faces, but with the
reversed logic (isPermanent = !isOnDemand)

Change-Id: I37ba604e5f105ca95a79a08b8cfc3d640df8b412
Refs: #1376
diff --git a/daemon/face/face.cpp b/daemon/face/face.cpp
index 1fb1109..08853aa 100644
--- a/daemon/face/face.cpp
+++ b/daemon/face/face.cpp
@@ -22,6 +22,7 @@
   : m_id(INVALID_FACEID)
   , m_isLocal(isLocal)
   , m_uri(uri)
+  , m_isOnDemand(false)
 {
   onReceiveInterest += bind(&increaseCounter<Interest>, _1, boost::ref(m_counters.getInInterest()));
   onReceiveData     += bind(&increaseCounter<Data>,     _1, boost::ref(m_counters.getInData()));
@@ -74,7 +75,7 @@
 Face::decodeAndDispatchInput(const Block& element)
 {
   /// \todo Ensure lazy field decoding process
-  
+
   if (element.type() == tlv::Interest)
     {
       shared_ptr<Interest> i = make_shared<Interest>();
@@ -89,7 +90,7 @@
     }
   else
     return false;
-  
+
   return true;
 }