Add support for sRGB attribute and fix creation on windows

build.rs

@@ -31,6 +31,7 @@ fn main() {
                                             "WGL_ARB_pixel_format".to_string(),
                                             "WGL_EXT_create_context_es2_profile".to_string(),
                                             "WGL_EXT_extensions_string".to_string(),
+                                            "WGL_EXT_framebuffer_sRGB".to_string(),
                                             "WGL_EXT_swap_control".to_string(),
                                         ],
                                         "1.0", "core", &mut file).unwrap();