Add support gtk-rs GLArea with epoxy.

[akhilman]

Add support GLArea with epoxy as GL provider.

[asny]

Is it something you need or just a suggestion? I have added features to be able to avoid the Glutin window. So if you want, you can disable default features and pick the features you want and implement your own gtk-rs window.

[akhilman]

Right now it is just a suggestion.

So if you want, you can disable default features and pick the features you want and implement your own gtk-rs window.

This is why I think Dust may work well as base for my Web / GTK application.
I'll try to implement GTK integration, but later.

[asny]

Ok, I will put it in my todo list as well, it should definitely be doable, but I don't have a lot of time. If you implement it, please let me know. I will be happy to add it as an alternative to the glutin window.
And happy to hear that you are considering using Dust! Please just ask if you need something.

[asny]

Closing this in favour of #292