Added ToolkitOptions class

ToolkitOptions allows the user to influence the implementation of
OpenTK.Platform at runtime.

Source/OpenTK/OpenTK.csproj

@@ -149,6 +149,7 @@
     <Compile Include="Math\Matrix4x3d.cs" />
     <Compile Include="Platform\DisplayDeviceBase.cs" />
     <Compile Include="Platform\Windows\WinInputBase.cs" />
+    <Compile Include="ToolkitOptions.cs" />
     <Compile Include="WindowBorder.cs">
       <SubType>Code</SubType>
     </Compile>
@@ -806,8 +807,5 @@
     </PostBuildEvent>
   </PropertyGroup>
   <ItemGroup />
-  <ItemGroup>
-    <Folder Include="Graphics\ES30\" />
-    <Folder Include="Graphics\OpenGL4\" />
-  </ItemGroup>
-</Project>
+  <ItemGroup />
+</Project>

Source/OpenTK/ToolkitOptions.cs

@@ -0,0 +1,85 @@
+#region License
+//
+// The Open Toolkit Library License
+//
+// Copyright (c) 2006 - 2013 the Open Toolkit library.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights to 
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace OpenTK
+{
+    /// <summary>
+    /// Enumerates options regarding OpenTK.Platform
+    /// implementations.
+    /// </summary>
+    public enum PlatformBackend
+    {
+        /// <summary>
+        /// Select the optimal OpenTK.Platform implementation
+        /// for the current operating system. This is the default
+        /// option.
+        /// </summary>
+        Default = 0,
+        /// <summary>
+        /// Prefer native OpenTK.Platform implementations. 
+        /// Platform abstractions such as SDL will not be considered,
+        /// even if available. Use this if you need support for multiple
+        /// mice or keyboards.
+        /// </summary>
+        PreferNative,
+        /// <summary>
+        /// Prefer an X11 OpenTK.Platform implementation,
+        /// even if a different implementation is available. This option
+        /// allows you to use X11 on Windows or Mac OS X when an
+        /// X11 server is installed. 
+        /// </summary>
+        PreferX11
+    }
+
+    /// <summary>
+    /// Contains configuration options for OpenTK.
+    /// <see cref="Toolkit.Init(ToolkitOptions)"/>
+    /// </summary>
+    public class ToolkitOptions
+    {
+        static ToolkitOptions()
+        {
+            Default = new ToolkitOptions();
+        }
+
+        /// <summary>
+        /// Get or set the desired <c>PlatformBackend</c>
+        /// for the OpenTK.Platform implementation.
+        /// </summary>
+        public PlatformBackend Backend { get; set; }
+
+        /// <summary>
+        /// Gets a <c>ToolkitOptions</c> instance with
+        /// default values.
+        /// </summary>
+        public static ToolkitOptions Default { get; private set; }
+    }
+}