This reverts commit 7f63ba3d.

* update link of models

* update en_version

* 0123-routine-docbug-fix

* Update metrics.rst

* update_to_develop

* fix

* update_to_1.2.1

* update_to_1.2.1

* polish_win_install (#562)

* polish_win_install

* follow_comments

* update_to_1.2.1

[cherry-pick]0114-cnapi-bugfix

* update_inference_link

* delete cuda 7.5 line in table

* add&update develop table

* integration_2tables

cherry pick - cn api fix bugs (#523)

* cn api fix bugs

* Update fluid_cn.rst

* Update lod_tensor.rst

- Modify some inaccurate descriptions
- Add the complete code example

* Update lod_tensor.rst

update_submodule_1.2

remove unused inference header

[cherry-pick] Update cn_api from develop to release/1.2

[cherry-pick] fix last_step for 1.2

* fix the ref for api_guides

* update_book

* fix for python3 support (#488)

* fix for python3 support
test=develop

* test=develop

* backward.rst

* Update backward.rst

* Update programming_guide.md (#493)

* update layers_nn

* Update layers_cn.rst

* Update layers_cn.rst

* update api_cn except layers

* update fluid_cn.rst

* Update metrics_cn.rst

* update_ciwhl

* update_2nd

* fix_3rd

* fix_deadlinks (#476)

* [infer][rl_note]develop=1.2 (#480)

* update_infer_toctree

* add_fluid

* Update release_note.rst

* update_install_doc

* update layers_cn_by_wh

* Fix some typo 1211 (#483)

* fix some typo

* Update nets_cn.rst

* update_version

* refine info of whl (#485)

* refine info of whl

* fix link for release-whls

* remove fast install info (#486)

* refine info of whl

* fix link for release-whls

* remove fast install info

* update layers_nn

* Update layers_cn.rst

* Update layers_cn.rst

* update api_cn except layers

* update fluid_cn.rst

* Update metrics_cn.rst

* update_ciwhl

* update_2nd

* fix_3rd

* fix_deadlinks (#476)

* [infer][rl_note]develop=1.2 (#480)

* update_infer_toctree

* add_fluid

* Update release_note.rst

Rl headline

update_infer_toctree