Spawn point system.

Hey we can place spawn points on the map now instead of hardcoding them!
Spawn points are simply invisible bare bones entities.

Content.Client/Commands/DebugCommands.cs

@@ -0,0 +1,39 @@
+using Content.Shared.GameObjects.Components.Markers;
+using SS14.Client.Interfaces.Console;
+using SS14.Client.Interfaces.GameObjects.Components;
+using SS14.Shared.GameObjects;
+using SS14.Shared.Interfaces.GameObjects;
+using SS14.Shared.IoC;
+
+namespace Content.Client.Commands
+{
+    internal sealed class ShowMarkersCommand : IConsoleCommand
+    {
+        // ReSharper disable once StringLiteralTypo
+        public string Command => "togglemarkers";
+        public string Description => "Toggles visibility of markers such as spawn points.";
+        public string Help => "";
+
+        public bool Execute(IDebugConsole console, params string[] args)
+        {
+            bool? whichToSet = null;
+            foreach (var entity in IoCManager.Resolve<IEntityManager>()
+                .GetEntities(new TypeEntityQuery(typeof(SharedSpawnPointComponent))))
+            {
+                if (!entity.TryGetComponent(out ISpriteComponent sprite))
+                {
+                    continue;
+                }
+
+                if (!whichToSet.HasValue)
+                {
+                    whichToSet = !sprite.Visible;
+                }
+
+                sprite.Visible = whichToSet.Value;
+            }
+
+            return false;
+        }
+    }
+}