* rcnn bs>1

* delete redundant comments

* bs>1 for YOLO

* support no label training

* fix load_crowd

* update to fit rbox

* add empty_ratio

* update configs

* support mask rcnn

* clean drop_empty for mot & keypoint

* refine is_crowd

* 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

* remove rbox-iou-ops dependence

* add pssdet model

* Add S2ANet model for Oriented Object Detection.

* update slim model

* fix skip quant

* support not pad gt in rcnn model

* add comment in reader