Silence unused imports warning in examples

glium reexports glutin and I think this
point needs to be stressed. So using glutin
from the reexport instead of the possibly
available extern crate is useful at least
in the examples otherwise users might not
realize that they don't have to add glutin
to their Cargo.toml.

Therefore, the lint is silenced instead of
being followed.

Link to the lint change that likely caused this:

rust-lang/rust#58805

Author: est31

examples/blitting.rs

@@ -5,6 +5,7 @@ extern crate glium;
 extern crate image;
 
 use std::io::Cursor;
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 
 mod support;

examples/deferred.rs

@@ -4,6 +4,7 @@ extern crate cgmath;
 extern crate image;
 
 use glium::index::PrimitiveType;
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 use std::io::Cursor;
 

examples/displacement_mapping.rs

@@ -3,6 +3,7 @@ extern crate image;
 extern crate glium;
 
 use std::io::Cursor;
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 
 mod support;

examples/fullscreen.rs

@@ -7,6 +7,7 @@ use std::io::Cursor;
 
 use glium::Surface;
 use glium::index::PrimitiveType;
+#[allow(unused_imports)]
 use glium::glutin::{self, ElementState, VirtualKeyCode, Event, WindowEvent};
 
 mod support;

examples/fxaa.rs

@@ -1,6 +1,7 @@
 #[macro_use]
 extern crate glium;
 
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 
 mod support;

examples/gpgpu.rs

@@ -1,6 +1,7 @@
 #[macro_use]
 extern crate glium;
 extern crate rand;
+#[allow(unused_imports)]
 use glium::glutin;
 use glutin::dpi::PhysicalSize;
 

examples/image.rs

@@ -4,6 +4,7 @@ extern crate image;
 
 use std::io::Cursor;
 
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 use glium::index::PrimitiveType;
 

examples/info.rs

@@ -1,6 +1,7 @@
 extern crate glium;
 
 fn main() {
+    #[allow(unused_imports)]
     use glium::{glutin, Api, Profile, Version};
 
     // building the display, ie. the main object

examples/instancing.rs

@@ -2,6 +2,7 @@
 extern crate glium;
 extern crate rand;
 
+#[allow(unused_imports)]
 use glium::{glutin, Surface};
 
 mod support;

examples/manual-creation.rs

@@ -19,6 +19,7 @@ There are three concepts in play:
 extern crate glium;
 
 use glium::Surface;
+#[allow(unused_imports)]
 use glium::glutin::{self, ContextTrait};
 
 use std::rc::Rc;