Add a variable to set opengl.dll filename on WGL

[CCnut]

Can a variable be added to set filename? Like QT_OPENGL_DLL.

glutin/glutin/src/api/wgl/display.rs

Line 53 in 9228126

OsStr::new("opengl32.dll").encode_wide().chain(Some(0).into_iter()).collect::<Vec<_>>();

[kchibisov]

I guess if you can place the library next to your binary and name it like that it'll just load it.

Though, we don't have a way to set a any variable to alter dynamic loading.

[kchibisov]

Maybe we should add a GLUTIN_WGL_OPENGL_DLL or something like that, but given that you can rename it could work just fine with put next to binary.

[CCnut]

I want opengl32.dll and opengl32sw.dll to coexist and be switchable to opengl32sw.dll when needed.