fix lsr bug in image classification

* Refine Image classification

* Add benchmark (fps) in MODEL_ZOO doc

* fix add map_type

* Refine arguments of ocr models.

* Add comments for issue of attention model in paddle1.5

* fix used

This reverts commit 5e41760f.

* minor fix for PaddleDetection

* fix SENet154_vd name

* fix bug in sharedmemory
* fix bug in sharedmemory

* fix reader, metrics, frameworks to increase universality of PaddleVideo

* change config files from .txt to .yaml

* fix input to use PyReader and modify on readme to fit new codes

* adjust code structure and modify configs and readme to fit standard

* modify links of pdparams in readme and scripts

* fix pickle.dump in python3 and modify on readme of attention_lstm

* add description of weights argument in eval/predict/inference_model.py

* add cascade gn

* add cascade mask gn config

* update configs

* fix train on VOC on multi-GPU hang

* not set persistable in parse_fetches

* fix rpn_only in cascade mask fpn

* fix rpn_only in cascade rcnn

* add gn doc

* refine cascade models

* update model zoo doc

* cascade-mask-fpn add

* add a global norm_type flag

* add group norm on fpn

* add gn on box head

* add faster rcnn fpn 50 gn config

* add mask branch norm

* update configs

* add yolov3_darknet cinfig comment

* fix commment

* add log_iter

* Add full configs example & refine doc

* refine docs

* add_ssd_config_demo

update readme