* update solov2 some detail

* fix check paddle version

* check md5 before load weights.

* support infer for SOLOv2

* add solov2 model

* fix train batch size

* add solov2_r101_vd_fpn_3x

* fix batch size and update modelzoo

* refactor code of solov2

* fix deploy/python

* check md5 after weights download

* fix voc mAP %.

* add roadsign_voc dataset and update FAQ

* Add roadsign_voc dataset, updatea FAQ.md, and add yolov3_voc and yolov3_coco config template files.

* remove configs/templates

* convert config template file to md file, update comment

* mv config annotation file to config_annotation.

* move to docs/advanced_tutorials/config_doc

* rename

* update style

* update 2019-->2020

* update yolov3_mobilenet_v1_roadsign.md

* addd preprocess as yolov3_reader

* remove yolov3_mobilenet_v1_roadsign.md and add yolov3_mobilenet_v1.md

* fix typo

* add py_func check in export_model

* refine error message

* fix voc dataset and docs

* add custom datsset demo

* add version check

* update version check & python version for cornerpool

* fix with_background in export model

* fix coco_eval background

* add yolov4

* Make logger less noisy

* Fix indent

* update check config

* fix slim/xx

* code for cornernet

* add doc

* refine custom op

* refine code from review comments

* refine doc

* update doc

* update code

* add cornernet_squeeze_mixup_cosine config

* update code

* update code

* add yolov3_mobilenet_v3

* refine transfer learn

* refine transfer learning doc

* Update checkpoint to use paddle 1.7 API

* Add new checkpoint support to `load_and_fusebn`

* Make yapf happy

* exit1 in travis failed

add libra rcnn, including
  * libra loss
  * libra fpn(bfp)
  * libra sampling

* load inference

* add doc

* add config file for tensorrt_infer

* add padding for rcnn preprocess

* refine code & doc

* refine cocoapi import

* fix infer when anno_path is None

- 1.add cn docs
- 2.fix fddb evaluate
- 3.fix get_shrink
- 4.delete FLAGS.dataset_dir

* Polish Reader to simplify preprocessing logic.
#  sample_transforms-> make batch -> batch_transforms in Reader.
* Clean some code
* Imporve yolov3_r50vd_dcn_obj365_pretrained_coco 41.4 to 41.8.
* Update all configs.

* Add cascade_rcnn_cls_aware_r200_vd_fpn_dcnv2_nonlocal_softnms model on oidv5 and obj365.
* Add obj365 config annotation
* Update docs.