[Examples] Cleaned up input device printing in GameWindowStates
[Examples] Calculate timing information in GameWindowStates
[OpenTK] More robust timing for UpdateFrame and RenderFrame

FrameEventArgs.Time should no longer drift from clock time measured
outside GameWindow.
[OpenTK] Implemented GameWindow.UpdateTime and RenderTime properties
[OpenTK] Corrected GameWindow.Update/RenderFrequency information
[Examples] Improve timing information; add vsync toggle