Removed NioTSO client and server

- NioTSO client isn't needed because we're using RayLib
- Added FreeSO's API server to handle most backend operations

server/tso.common/MeshSimplify/MSTriangle.cs

@@ -0,0 +1,12 @@
+using Microsoft.Xna.Framework;
+
+namespace FSO.Common.MeshSimplify
+{
+    public class MSTriangle
+    {
+        public int[] v = new int[3];
+        public double[] err = new double[4];
+        public bool deleted, dirty;
+        public Vector3 n;
+    }
+}