Removed OpenTK.Graphics.Glu class (reason: deprecated upstream; most functionality provided by OpenTK math; not compatible with OpenGL 3.0+.) OpenTK.Graphics.Glu can be accessed through OpenTK.Compatibility.
Added OpenGL|ES-specific ErrorHelper classes.
Moved OpenTK.Graphics.DisplayDevice and OpenTK.Graphics.DisplayResolution to the root OpenTK namespace (reason: their functionality is not specific and does not depend on OpenTK.Graphics).
Split Graphics*Exception classes into different files.
Made GraphicsErrorException public (reason: necessary for OpenTK.Compatibility).
WinRawInput now correctly subclasses WinGLNative or WinGLControl. WinRawKeyboard now correctly responds to events.
Removed T10_GLSL_Cube.cs which was erroneously moved outside the Examples/Tutorial directory.
Updated INativeWindow, IGameWindow and IGLControl interfaces.
Updated examples to use the new GameWindow interface.
Added documentation to GameWindow.
Improved GameWindow error handling. More defensive programming.
Updated the ExampleLauncher to not process exceptions. Updated the IExample interface to contain the Launch method. Updated examples and the ExampleLauncher according to the IExample interface.
Synced with gl3 branch.