* s2anet fix export and deploy

* remove redundant code

* fix cpp for s2anet deploy

* fix bug of get_categories

* rename poly_to_rbox to poly2rbox

* add some comment for function

* add mot data

* fix operators, source

* fix data source transform

* fix parse_dataset register_op

* fix scale_factor, RandomAffine

* add assert for check

* fix ci

remove doubled words

* fix voc eval

* remove debug code

* add comments

* update comment for collate_batch

* refine yolov3 configs

* fix dataset problem

* add ext_op build doc, test=fix_document

* add note for JetPack version with machine

* update doc on develop, test=document_fix

* update dependency of ppdet and paddle, test=document_fix

* update docs, test=document_fix

* fix some docs error

* add ttfnet enhance

* add doc

* fix pafnet training

* move ssld model, test=document_fix

* fix typo, test=document_fix

* add ppyolov2

* fix bugs and modify docs

* modify code and doc according to review

* fix bugs while resolving conflicts

* update README

* update doc, test=document_fix

* add citation

* update citation and ppyolo doc

* add PP-YOLO tiny

* add pssdet model

* add senet

* add annotations according to review

* Add S2ANet model for Oriented Object Detection.

* update slim model

* fix skip quant

* add Distill model
* add distill+prune

* add fcos ttfnet coment, update modelzoo

* fix ttfnet coment