* merge upstream

* clean code

* add batch_size in keypoint_detector

* add sparsercnn

* update sparsercnn

* Add DETR

* drop return_pad_mask in PadBatch

* fix_install_docs

* fix_install_docs2

* fix bs=2 of FCOS

* fix bs=2 of ttfnet

* fix cascade deploy

* speedup by paddle.expand

* add deepsort export model, reid infer

* fix jde_yolov3 metric

* fix deepsort deploy

* fix doc, clean code

* add mot deploy infer image, add run_benchmark

* fix not find dirent.h on windows

* using cv::glob replace fileststem, fileststem need std++17

* add document for keypoint dataset preparation

* test=document_fix

* test=document_fix

* 关键点文档中json示例格式化显示，test=document_fix

* add mot keypoint unite python infer

* fix mot pose fps

* reorganize the code, and fix bug

* fix typo

* remve comment

* reorganize code

* Revert "reorganize code"

This reverts commit 4f928c3a46b264ba8815978b914bf81a46b66b62.

* set weight

* set default config

* fix code style

* add solov2 enhance model

* refine keypoint deploy

* fit video infer

* fix post process

* update comments for keypoint_batch_size

* fix warning when result is empty

* fix warning when result is empty

add dark deploy supported, mpii deploy supported;

* add random resize and crop

* update

* update

* modified freeze at in resnet

* freeze_at should less than num_stage

* support --eval for s2anet

* add spine dataset and config yml for s2anet

* add doc for s2anet

* update doc

* fix typo, test=document_fix

* add some comments, and update import

* add mot score to txt results

* fix mot install typo

* add epoch for deepsort

* fix paddle no_grad

* deploy infer save image txt

* fix bug when benchmark=True

* split warmup and repeat