Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into deadlint...

Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into deadlint push origin deadlinks

doc/v2/api/config/layer.rst

@@ -460,6 +460,11 @@ multi_binary_label_cross_entropy_cost
 ..  autoclass:: paddle.v2.layer.multi_binary_label_cross_entropy_cost
     :noindex:
 
+classification_cost
+-------------------
+.. autoclass:: paddle.v2.layer.classification_cost
+   :noindex:
+
 huber_regression_cost
 -------------------------
 ..  autoclass:: paddle.v2.layer.huber_regression_cost