* refactor rbox

* modify the code of save results

* fix some problem

* add .gitignore in dataset/dota

* fix test anno path

* refactor s2anet to support batch_size > 1

* fix problem of inference

* support batch_size > 1 for training

* fix empty results

* fix dota eval

* fix configs of s2anet_head

* modify s2anet_spine_1x to 73 mAP

* refactor ext op and add matched rbox iou

* replace rbox_iou_ops with ext_op

* fix class init when import ppdet files

* fix problem of s2anet while deploying

* correct problem of s2anet TestReader

* add dota default category

* set lr for 4 card as default, and update

* s2anet update

* remove np anchor

* clean code of s2anet

* fix for paddle==2.1.0

* remove debug info

* update comment

* 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

* 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

* 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 script of dota_2_coco

* add args for dota_to_coco

* add script to generate test result of dota

* add loss weight for s2anet

* fix dy2st for s2anet

* fix code style

* Add S2ANet model for Oriented Object Detection.