remove command argument train.py from the document, which is added by mistake.

*  fix for FluidDoc/doc/fluid/beginners_guide/install/index_cn.rst in develop

Done

* fix the word error in timeline doc, test=document_preview

* fix wrong word, test=document_preview

* add 1.5.1 inference lib download path for windows

* re-organize the doc format

* ok

* ok

* ok

* add check_approval

* check approval

* check approval

* check approval

* check approval

* check approval

* check approval

* add check_approval

* add check_approval

* add check_approval

* add check_approval

* add check_approval

* change api

* change api

* add 1.5.1 whl and fix some bugs (#1010)

* add windows install whl

* whl and bug

* fix some bugs

* update 1.5.1 cn API

* add url

* dygraph translation

* cn doc bug fix

* translate dygraph according to 1.5.1 website + bug fix

* ok

* ok

* ok

* add check_approval

* check approval

* check approval

* check approval

* check approval

* check approval

* check approval

* add check_approval

* add check_approval

* add check_approval

* add check_approval

* add check_approval

* remove useless compile option on MacOS

* this will fix default cuda version

fix dead chain at op_notes
fix Sharelod() to ShareLoD()

* test=develop, add fix_install_doc_with_gpu_docker_usage

* refine format

* fix install command wrong

* give a detail description on CUDA driver insufficient issue test=develop

* remove the useless words test=develop

* fix the word test=develop

* fix the word test=develop

compile_CentOS.md
compile_Ubuntu.md
install_CentOS.md
install_Ubuntu.md

* fix the doc for 1.5 test=develop

* test=develop

* Update fleet_api_howto_cn.rst

* Update fleet_api_howto_cn.rst

* Update fleet_api_howto_cn.rst

* test=develop, update install doc

* add setuptools dependency

* Update compile_Ubuntu.md

update cudnn version

* Update install_Ubuntu.md

update cudnn version

* Update install_CentOS.md

update cudnn version

* test=develop, refine ubuntu cuda support

* test=develop, refine ubuntu cuda support

* test=develop, refine python support on python3.5

* fix python2 in ubuntu16.04 need gcc 5.4

* add nccl related doc

* refine doc

* add gpu fast install doc

* refine command of pip

* add avx off for mac complie

* refine code

* refine doc

* fix python only support 64bit

* fix doc problem

* refine doc

* remove centos7 support cuda8 compile

* fix centos6 compile not support

* Add best practice

Create a special case for dygraph-node when running gen_doc.