Better OpenGL ES support

[torkleyy]

My phone: LG P880 (4x hd)

I can't use glutin on my phone because this line causes the application to panic.

I'm not sure if this is the reason but it has some sort of nvidia Tegra chip.

Is it possible to handle that case or why was it left out?

[torkleyy]

@tomaka The bug is in line 214 because my egl_version is (1, 4).

[tomaka]

The bug is the fact that it's unimplemented, not the fact that version contains None.

The unimplemented! is supposed to be the code that automatically detects which version of OpenGL ES is supported.

[torkleyy]

@tomaka I see, ok. However, I tried to work around that problem by specifying a version, and I got another panic because this line caused a NoAvailablePixelFormat error (it seems the requested configuration is not supported).

[torkleyy]

@tomaka Same error with Nexus 5X. I'd really like to fix this, but I don't know how to implement it.

[kchibisov]

Fixed in #1435.