Make EditSession closeable for easy flushing

worldedit-core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -134,7 +134,7 @@ import javax.annotation.Nullable;
  * using the {@link ChangeSetExtent}.</p>
  */
 @SuppressWarnings({"FieldCanBeLocal"})
-public class EditSession implements Extent {
+public class EditSession implements Extent, AutoCloseable {
 
     private static final Logger log = Logger.getLogger(EditSession.class.getCanonicalName());
 
@@ -636,6 +636,14 @@ public class EditSession implements Extent {
         return bypassNone.getEntities();
     }
 
+    /**
+     * Closing an EditSession {@linkplain #flushSession() flushes its buffers}.
+     */
+    @Override
+    public void close() {
+        flushSession();
+    }
+
     /**
      * Communicate to the EditSession that all block changes are complete,
      * and that it should apply them to the world.