* 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

* 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

* Add S2ANet model for Oriented Object Detection.