Deprecating this Crate

[sanbox-irl]

Hello!

I would like to deprecate this crate. I think that the next release (0.13.0) will be its last.

If anyone uses this extensively, I am willing to transfer it to them.

If there is a chorus of those who would like for this to maintained as-is, that can be discussed.

The reason I want to stop maintaining it is that I don't think it's very well used, and the maintenance burden, especially with coordinating glium/glutin/winit/glutin-winit can be quite a lot.