* share train_batch_size from reader to model

* update floor_divide

* add makedirs for dumping config

* check md5 after weights download

* move train_batch_size sync from load_config to merge_config

* warning when YOLOv3Loss.batch_size setting

* add batch_size in YOLOv3Loss for backward compatable.

* sync TrainReader.batch to global train_batch_size

* fix voc mAP %.

Co-authored-by: NKaipeng Deng <dengkaipeng@baidu.com>

* add roadsign_voc dataset

* fix some typo

* fix deadlink in docs/tutorials/INSTALL_cn.md, slim/README.md and slim/extensions/distill_pruned_model/README.md

* update version require for ppyolo

* add COCO test-dev eval config and doc

* add PPYOLO
Co-authored-by: Nlongxiang <longxiang@baidu.com>

add htc model 

* add py_func check in export_model

* refine error message

* Add `matrix_nms` op

* Make OP registration more robust

Add gridmask and random erasing methods