Move to one display. There's no reason to have two displays here -- the
comment stated that one should touch GLX and one should touch window
events, and that they should be touched from different threads, but the
current code wasn't this careful.
Just use one Display connection.
Now, the only supported EGL platform is Android. We might eventually add
back support for EGL/X11 or EGL/Wayland, but it will have to be
architected differently.
Yes, this is a fancy new feature, but our Wayland support was
particularly bitrotten, and ideally this would be handled by a platform
layer like SDL. If not, we can always add this back in when GLInterface
has caught up. We might be able to even support wxWidgets and GL
together with subsurfaces!
