* GLControl.cs: More defensive checks for null GraphicsModes.
Set flags, context version and GraphicsMode before calling
InitializeComponents(), as the latter might cause the context to be
created (and we need this information before creating the context).
Fixes ArgumentNullException on Linux.
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.
members are accessed (issue [#1141]: "Unhandled exception in
GlControl possible bug in rev 2207"). Throw ObjectDisposedException
if public members are accessed after the GLControl has been
disposed. Force the create/recreation of the control if a public
member is called and the control handle or context does not exist.