Functional networkevent validation, functional single player saving, requireditem ui texts, titlescreen & loading

Subsurface/Items/Components/Machines/Steering.cs

@@ -24,6 +24,11 @@ namespace Subsurface.Items.Components
             get { return targetVelocity;}
             set 
             {
+                if (float.IsNaN(value.X) || float.IsNaN(value.Y))
+                {
+                    targetVelocity = Vector2.Zero;
+                    return;
+                }
                 targetVelocity.X = MathHelper.Clamp(value.X, -100.0f, 100.0f);
                 targetVelocity.Y = MathHelper.Clamp(value.Y, -100.0f, 100.0f);
             }