Popup message notifications. (#125)

* Popup message system v1

* Networking for the popup notifications.

Ship it.

Content.Server/ServerNotifyManager.cs

@@ -0,0 +1,63 @@
+using Content.Server.Interfaces;
+using Content.Shared;
+using Content.Shared.Interfaces;
+using SS14.Server.Interfaces.Console;
+using SS14.Server.Interfaces.GameObjects;
+using SS14.Server.Interfaces.Player;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.Interfaces.Network;
+using SS14.Shared.IoC;
+using SS14.Shared.Map;
+using SS14.Shared.Utility;
+
+namespace Content.Server
+{
+    public class ServerNotifyManager : SharedNotifyManager, IServerNotifyManager
+    {
+#pragma warning disable 649
+        [Dependency] private IServerNetManager _netManager;
+#pragma warning restore 649
+
+        private bool _initialized;
+
+        public void Initialize()
+        {
+            DebugTools.Assert(!_initialized);
+
+            _netManager.RegisterNetMessage<MsgDoNotify>(nameof(MsgDoNotify));
+            _initialized = true;
+        }
+
+        public override void PopupMessage(GridLocalCoordinates coordinates, IEntity viewer, string message)
+        {
+            if (!viewer.TryGetComponent(out IActorComponent actor))
+            {
+                return;
+            }
+
+            var netMessage = _netManager.CreateNetMessage<MsgDoNotify>();
+            netMessage.Coordinates = coordinates;
+            netMessage.Message = message;
+            _netManager.ServerSendMessage(netMessage, actor.playerSession.ConnectedClient);
+        }
+
+        public class PopupMsgCommand : IClientCommand
+        {
+            public string Command => "srvpopupmsg";
+            public string Description => "";
+            public string Help => "";
+
+            public void Execute(IConsoleShell shell, IPlayerSession player, string[] args)
+            {
+                var entityMgr = IoCManager.Resolve<IEntityManager>();
+
+                var source = EntityUid.Parse(args[0]);
+                var viewer = EntityUid.Parse(args[1]);
+                var msg = args[2];
+
+                entityMgr.GetEntity(source).PopupMessage(entityMgr.GetEntity(viewer), msg);
+            }
+        }
+    }
+}