adding a key press to exit the image window

The code used to ruin on an infinite while loop. I couldn't close the image window while the programming is running. Inorder to make it more user friendly I have just added a key press to close the window when an esc key or 'q' is pressed.

wrappers/python/examples/align-depth2color.py

@@ -71,7 +71,11 @@
         images = np.hstack((bg_removed, depth_colormap))
         cv2.namedWindow('Align Example', cv2.WINDOW_AUTOSIZE)
         cv2.imshow('Align Example', images)
-        cv2.waitKey(1)
+        key = cv2.waitKey(1)
+        # Press esc or 'q' to close the image window
+        if key & 0xFF == ord('q') or key == 27:
+            cv2.destroyAllWindows()
+            break
 finally:
     pipeline.stop()