Merge dygraph branch into master branch.
Co-authored-by: NFDInSky <48318485+FDInSky@users.noreply.github.com>
Co-authored-by: Nsunxl1988 <47514455+sunxl1988@users.noreply.github.com>
Co-authored-by: Nwangguanzhong <jerrywgz@126.com>
Co-authored-by: Nwangxinxin08 <69842442+wangxinxin08@users.noreply.github.com>
Co-authored-by: Nwanghuancoder <wanghuancoder@163.com>
Co-authored-by: Ncnn <liuhui29@baidu.com>
Co-authored-by: NGuanghua Yu <742925032@qq.com>
Co-authored-by: NKaipeng Deng <dengkaipeng@baidu.com>
Co-authored-by: Nroot <root@bjyz-sys-gpu-kongming0.bjyz.baidu.com>

* support ppyolo for kunlun

test=document_fix

* support mask_rcnn for kunlun

* minor

* update ppyolo_mobilenet_v3 large & small

* support visualdl in preprocess data

* support most preprocess op

test=document_fix

* update some link in README

* fix product news

* Update QUICK_STARTED_cn.md (#1757)

fix typo

* cherry-pick #1757 and #1473, test=document_fix

* update v0.5 release note

* update some comments

* add ppyolo_voc

* Add PrepareData-->SelectModel-->Train-->Eval-->Test-->Infer-->Slim-->Deploy document DetectionPipeline.md, test=document_fix

* Correct Format of README_en.md
* Update README_cn.md
* Correct details in README_en.md

* update solov2 some detail

* fix check paddle version

* update cpp build script

* rename document and update script

* set WITH_MKL=ON for pass CI

* set WITH_GPU=OFF and WITH_TENSORRT=OFF for pass CI

* check md5 before load weights.

* add TX2 cpp build document and benchmark

* turn WITH_MKL=ON

* add tensorrt version

* set WITH_GPU=OFF for CI

* keep same as TX2_build

* enhance voc to coco docs

* fix voc annotation float type