Engine(-Twitter),Frontend: avoid Close warning dialog (closes: #1093)

src/Engine-Twitter/Protocols/Twitter/TwitterProtocolManager.cs

@@ -115,6 +115,12 @@ protected bool HasTokens {
             }
         }
 
+        public override bool HiddenPresenceStatus {
+            get {
+                return true;
+            }
+        }
+
         public TwitterProtocolManager(Session session) : base(session)
         {
             Trace.Call(session);

src/Engine/Protocols/IProtocolManager.cs

@@ -67,6 +67,10 @@ PresenceStatus PresenceStatus {
             get;
         }
 
+        bool HiddenPresenceStatus {
+            get;
+        }
+
         void Connect(FrontendManager frontendManager, ServerModel server);
         void Disconnect(FrontendManager frontendManager);
         void Reconnect(FrontendManager frontendManager);

src/Engine/Protocols/ProtocolManagerBase.cs

@@ -86,6 +86,12 @@ public virtual PresenceStatus PresenceStatus {
             }
         }
 
+        public virtual bool HiddenPresenceStatus {
+            get {
+                return false;
+            }
+        }
+
         public abstract string NetworkID {
             get;
         }

src/Frontend-GNOME/Views/Chats/ProtocolChatView.cs

@@ -168,7 +168,7 @@ public override void Close()
                     ownedChats++;
                 }
             }
-            if (ownedChats > 1) {
+            if (!ProtocolManager.HiddenPresenceStatus && ownedChats > 1) {
                 Gtk.MessageDialog md = new Gtk.MessageDialog(
                     Frontend.MainWindow,
                     Gtk.DialogFlags.Modal,

src/Frontend-Tests/Mocks/MockProtocolManager.cs

@@ -35,6 +35,12 @@ public Session Session {
             }
         }
 
+        public bool HiddenPresenceStatus {
+            get {
+                return false;
+            }
+        }
+
         public string NetworkID {
             get {
                 return "MockProtocolManagerNetwork";

src/Frontend/ChatViewSyncManager.cs

@@ -79,8 +79,8 @@ public void Add(ChatModel chatModel)
                          Math.Round(duration) + " ms");
 #endif
 
-            OnChatAdded(chatModel, chatId, chatType, chatPosition,
-                        protocolManager, protocolManagerType);
+            RaiseChatAdded(chatModel, chatId, chatType, chatPosition,
+                           protocolManager, protocolManagerType);
         }
 
         /// <remarks>
@@ -290,10 +290,10 @@ void SyncWorker(ChatModel chatModel)
             }
         }
 
-        void OnChatAdded(ChatModel chatModel, string chatId,
-                         ChatType chatType, int chatPosition,
-                         IProtocolManager protocolManager,
-                         Type protocolManagerType)
+        void RaiseChatAdded(ChatModel chatModel, string chatId,
+                            ChatType chatType, int chatPosition,
+                            IProtocolManager protocolManager,
+                            Type protocolManagerType)
         {
             if (ChatAdded != null) {
                 ChatAdded(this,