Rust bindings for EGL

Linking

When using OpenGL ES with rust-egl, it is necessary to place a dummy extern at the top of your application which links libEGL first, then GLESv1/2. This is because libEGL provides symbols required by GLESv1/2. Here's how to work around this:

```

[link(name = "EGL")]

[link(name = "GLESv2)]

extern {} ```