test=develop test=document_fix

* fix Layer and Pool2D api, test=develop

* update label_smooth_cn.rst, test=develop

* fix Layer and Pool2D api, test=develop

* update label_smooth_cn.rst, test=develop

* update Conv2D_cn.rst, test=develop

* update conv and pool op, test=develop

* fix Conv2DTranspose_cn.rst, Conv2D_cn.rst, test=develop

* add comment for class Layer, test=develop

* add comment for class Layer, test=develop

* add comment for dygraph layer, test=develop

* add comment for dygraph layer, test=develop

* add comment for name, test=develop

* fixed one error of api_cn

* fixed some errors of api_cn

* fixed some errors of api_cn

* fixed two errors.

* fixed two errors

* fixed one error.

* fixed one error

* fixed one error.

* fixed two errors.

* fixed one error.

* fixed two errors

* fixed two links

* synchronize api_cn with the api_en of develop.

* updated develop/api_cn

* update the api_cn of develop

* update api_cn of develop

* fixed some errors

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* Delete .DS_Store

* fixed some wrong links

* fixed two links

* fixed two links and some error.

* fixed some errors.

* fixed two links