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.Shared/GameObjects/Components/Markers/SharedSpawnPointComponent.cs

@@ -0,0 +1,9 @@
+using SS14.Shared.GameObjects;
+
+namespace Content.Shared.GameObjects.Components.Markers
+{
+    public class SharedSpawnPointComponent : Component
+    {
+        public sealed override string Name => "SpawnPoint";
+    }
+}