Do not call SDL.GetVersion unless requested

Source/OpenTK/Platform/SDL2/Sdl2.cs

@@ -29,6 +29,7 @@ using System.Runtime.InteropServices;
 #endregion
 
 using System;
+using System.Diagnostics;
 using System.Security;
 using System.Runtime.InteropServices;
 
@@ -46,17 +47,25 @@ namespace OpenTK.Platform.SDL2
         #endif
 
         public readonly static object Sync = new object();
-        public readonly static Version Version;
+        static Nullable<Version> version;
-
+        public static Version Version
-        static SDL()
+        {
+            get
             {
                 try
                 {
-                GetVersion(out Version);
+                    if (!version.HasValue)
+                    {
+                        version = GetVersion();
+                    }
+                    return version.Value;
                 }
                 catch
                 {
                     // nom nom
+                    Debug.Print("[SDL2] Failed to retrieve version");
+                    return new Version();
+                }
             }
         }
 
@@ -140,6 +149,12 @@ namespace OpenTK.Platform.SDL2
         [SuppressUnmanagedCodeSecurity]
         [DllImport(lib, CallingConvention = CallingConvention.Cdecl, EntryPoint = "SDL_GetVersion", ExactSpelling = true)]
         public static extern void GetVersion(out Version version);
+        public static Version GetVersion()
+        {
+            Version v;
+            GetVersion(out v);
+            return v;
+        }
 
         [SuppressUnmanagedCodeSecurity]
         [DllImport(lib, CallingConvention = CallingConvention.Cdecl, EntryPoint = "SDL_GetWindowID", ExactSpelling = true)]