* clean code of s2anet

* fix for paddle==2.1.0

* remove debug info

* update comment

* update link to release/2.2

* add the config of fairmot_headtracking

* mot video decode to images

* add infer_dir for mot

* fix export and unite pose infer

* remove task in mot source

* set image_dir

* update doc

* add sparse rcnn config

* update

* update

* remove redundant code

* simplify code

* fix tracker trt, add tracker to infer_cfg yml

* fix doc and deploy tracker

* add flops

Besides removing unnecessary imports, this also fixes the missing logger module in test_architectures.py within the static directory.

* merge upstream

* clean code

* add batch_size in keypoint_detector