SimpleWindowBuilder.build should be generic over EventLoop<T>

[waynr]

This allows me to add my own events to the event loop via
winit::event::Event, prior to this change I was seeing errors that looked
like the following:

error[E0308]: mismatched types
   --> src/main.rs:62:16
    |
62  |         .build(&el);
    |          ----- ^^^ expected `&EventLoop<()>`, found `&EventLoop<MyEvent>`
    |          |
    |          arguments to this method are incorrect
    |
    = note: expected reference `&EventLoop<()>`
               found reference `&EventLoop<MyEvent>`

I haven't tried running any tests, just thought I would get feedback from
maintainers before doing any more.

[est31]

LGTM, I think it's good to have this change.

[notgull]

I think a better solution would be to work a no-generic clonable owned display handle into winit, as proposed here.

[waynr]

I think a better solution would be to work a no-generic clonable owned display handle into winit, as proposed rust-windowing/glutin#1582 (comment).

@notgull I'm still fairly new to graphics programming in general let alone glium/glutin/winit...but I don't understand how that solves the problem. Does obviate the need for SimpleWindowBuilder somehow such that I can use winit::window::WindowBuilder with its already generic build method?

Not disputing that your proposed solution is better, but is there anything particularly wrong with this approach that should prevent it being merged before the better-in-the-long-term solution is available? Is it possible someone is actually depending on SimpleWindowBuilder taking a non-generic EventLoop<()>?

[notgull]

Ah my bad, misunderstood the problem. Yeah that wouldn't work