Add extern glutMouseWheelFunc.

glut.rs

@@ -9,7 +9,7 @@
 
 /* automatically generated by rust-bindgen */
 
-use glut::bindgen::{glutCreateWindow, glutDestroyWindow, glutDisplayFunc, glutMouseFunc};
+use glut::bindgen::{glutCreateWindow, glutDestroyWindow, glutDisplayFunc, glutMouseFunc, glutMouseWheelFunc};
 use glut::bindgen::{glutKeyboardFunc, glutGetModifiers, glutMotionFunc, glutPassiveMotionFunc};
 use glut::bindgen::{glutGet, glutGetWindow};
 use glut::bindgen::{glutInit, glutInitDisplayMode, glutPostRedisplay, glutReshapeFunc};
@@ -489,6 +489,8 @@ pub fn glutKeyboardFunc(func: *u8);
 
 pub fn glutMouseFunc(func: *u8);
 
+pub fn glutMouseWheelFunc(func: *u8);
+
 pub fn glutMotionFunc(func: *u8);
 
 pub fn glutPassiveMotionFunc(func: *u8);