* add sge attention on fpn

* add iou head

* add config, fix head

* fix iou offset weight

* fix fairmot centerhead

* add centernet

* add centernet

* add r50 for centernet

* support deploy for centernet

* add doc

* update pretrain

* clean code

* update r50 doc

* unify for_mot

* update code according to review

* update doc

* refine preprocess

* update doc

* update PicoDet Architecture and config

* add hardnet85 fairmot

* fix hardnet85

* add centernet hardnet fpn, fix config

* update modelzoo

* update modelzoo readme

* remove comments

* add hardnet num_layers assert

* fix hardnet85 config

* add hrnet18 fairmot

* add lite hrnet_w18

* add hrnet dlafpn

* update hrnet18_dlafpn modelzoo

* hrnet18dlafpn modelzoo

* add comments

* set neck not none, update modelzoo

* Update PicoDet adn GFl

* add gfl model and PicoDet

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

* add solov2 enhance model

* fix for_mot in PPYOLOTinyFPN and PPYOLOPAN

* fix yolo_fpn

* add fairmot

* rename pretrain_weights

* add comments; reuse focal loss and convnorm

* update comments

* jde and deepsort: model

* fix name of ConvNormLayer for fcos solov2

* fix name in other head convbn

* fix yolo name, fix ttf_head name, test=document_fix

* add ttfnet enhance

* add doc

* fix pafnet training

* add ppyolov2

* fix bugs and modify docs

* modify code and doc according to review

* fix bugs while resolving conflicts

* add PP-YOLO tiny

* add senet

* add annotations according to review

* add fcos ttfnet coment, update modelzoo

* fix ttfnet coment