This takes the latest glutin master to port Alacritty to the EventLoop
2.0 rework.
This changes a big part of the event loop handling by pushing the event
loop in a separate thread from the renderer and running both in
parallel.
Fixes#2796.
Fixes#2694.
Fixes#2643.
Fixes#2625.
Fixes#2618.
Fixes#2601.
Fixes#2564.
Fixes#2456.
Fixes#2438.
Fixes#2334.
Fixes#2254.
Fixes#2217.
Fixes#1789.
Fixes#1750.
Fixes#1125.
This switches our own `copypasta` crate with the more standardized
`clipboard` library, which allows us to get rid of the `xclip`
dependency on X11.
Additionally, this lays the foundation for native Wayland clipboard
support once the clipboard crate is updated (or a fork is created).
Fixes#5.