作用：
当我们用Fragment或是Activity做为Glide的Context，Glide 实现当Fragment或Activity销毁时，图片停止加载。
<code>
/**
An interface for listener to {@link android.app.Fragment} and {@link android.app.Activity} lifecycle events.
*/
public interface LifecycleListener {
/**
Callback for when {@link android.app.Fragment#onStart()}} or {@link android.app.Activity#onStart()} is called.
*/
void onStart();
/**
Callback for when {@link android.app.Fragment#onStop()}} or {@link android.app.Activity#onStop()}} is called.
*/
void onStop();
/**
Callback for when {@link android.app.Fragment#onDestroy()}} or {@link android.app.Activity#onDestroy()} is called.
*/
void onDestroy();
}
</code>
