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/udp-channel.cpp b/daemon/face/udp-channel.cpp
index 9151830..390b412 100644
--- a/daemon/face/udp-channel.cpp
+++ b/daemon/face/udp-channel.cpp
@@ -80,7 +80,7 @@
 {
   ChannelFaceMap::iterator i = m_channelFaces.find(remoteEndpoint);
   if (i != m_channelFaces.end()) {
-    i->second->setPermanent(true);
+    i->second->setOnDemand(false);
     onFaceCreated(i->second);
     return;
   }
@@ -104,7 +104,7 @@
     throw Error("Failed to properly configure the socket. Check the address ("
                 + std::string(e.what()) + ")");
   }
-  createFace(clientSocket, onFaceCreated, true);
+  createFace(clientSocket, onFaceCreated, false);
 }
 
 void
@@ -157,11 +157,11 @@
 shared_ptr<UdpFace>
 UdpChannel::createFace(const shared_ptr<ip::udp::socket>& socket,
                        const FaceCreatedCallback& onFaceCreated,
-                       bool isPermanent)
+                       bool isOnDemand)
 {
   udp::Endpoint remoteEndpoint = socket->remote_endpoint();
 
-  shared_ptr<UdpFace> face = make_shared<UdpFace>(boost::cref(socket), isPermanent);
+  shared_ptr<UdpFace> face = make_shared<UdpFace>(boost::cref(socket), isOnDemand);
   face->onFail += bind(&UdpChannel::afterFaceFailed, this, remoteEndpoint);
 
   onFaceCreated(face);
@@ -204,7 +204,7 @@
 
     face = createFace(clientSocket,
                       onFaceCreatedNewPeerCallback,
-                      false);
+                      true);
   }
 
   //Passing the message to the correspondent face
@@ -233,7 +233,7 @@
   while (next != m_channelFaces.end()) {
     ChannelFaceMap::iterator it = next;
     next++;
-    if (!it->second->isPermanent() &&
+    if (it->second->isOnDemand() &&
         !it->second->hasBeenUsedRecently()) {
       //face has been idle since the last time closeIdleFaces
       //has been called. Going to close it