In OpenTK 1.1, GraphicsMode queries the platform for a mode id lazily.
By delaying VisualInfo selection until the GraphicsContext is constructed
we ensure that a concrete GraphicsMode is selected and ready for use.
Removed OpenTK.Platform.Utilities.CreateWindowInfo and made the platform-specific CreateWindowInfo methods public (e.g. CreateX11WindowInfo).
Moved Mono Windows.Forms-specific code into X11GLControl.
Removed OpenTK.Platform.Utilities.IsIdle.
Removed obsolete methods from OpenTK.Platform.Utilities.
Marked OpenTK.Platform.Utilities.CreateGraphicsContext as obsolete (use GraphicsContext constructor instead).
Made IWindowInfo implementations private.