* add model zoo document file

* refine readme and fix train bug

* update darknet53 pretrain link

* update weights path

* Rename object_detection to PaddleDetection
* Small fix for doc

* Revise README.md

* Revise `GETTING_STARTED.md`

* Revise `INSTALL.md`

* Add `CONFIG.md`

* Fix RetinaNet backbones in README

* Fix cascade backbones in README

* Fix capitalization

* Replace demo images and update visualize funcall

* Revise `DATA.md`

* Fix link to `DATA.md`

* Fix capitalization

* refine bbox visualize

* use different color for different categories

* change color range

* fix gan readme

* add multi process implementation for yolov3

* rcnn config

* code migration for mutiple process

* Clean up config files

- reorder: batch_size -> data_set -> sample_transforms -> batch_transforms -> worker -> other
- unify bool values, lower case true/false
- remove `null` values
- remove `shuffle` settings, covered by default values

* Update ResNet50 pretrained weight url

* Remove `use_padded_im_info` settings, covered by default value

* Update README.md

* fix x0,y0 out of bound

* clip x1/y1

* Add GC in train.py by defalut and change data co dataset in configs
* Update docs/INSTALL.md
* Enable build_strategy.enable_inplace = True

* test=develop add retinanet_r101 and delete needless configures in data feeder

* test=develop
add retinanet_r101 and delete needless configures in data feeder

* fix infer and conflict attribute

* Fix missing `absolute_import`

* Fix cycle import

* Fix missing export

* Remove some extra blank line and whitespaces

* Rename `create_feeds` -> `create_feed`

* Fix minor issues in tool scripts

* Add ipython notebook demo

* Tweak visualization bbox label style

* download 3 VOC dataset

* clean code

* fix name map

* refine log

* refine dataset exists check

* add merge_and_create_list

* remove create_list

* clean code

* refine TODO

* not generate label list

* refine comment

* remove useless import

* fix test and infer for ctcn

* add instruction to dataset/ctcn/readme

* add VOC visualize

* fixn ssd_mobilenet_v1_voc.yml

* use default label

* clean TestFeed dataset config

* fix voc default label

* fix format

* fix as review

* revert voc default

* use defult label for all

* enable batch size != 1

* Support download VOC dataset.

* modify the crop operator

* modify the judgment

* modify the judgment v2

* modify the data_feed.py

* modify the readme and add labelme2coco code

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README_cn.md

* Update README_cn.md

* Update README_cn.md

* Update README_cn.md

* Update README_cn.md

* Update README_cn.md

* Update README.md

* Update README_cn.md

* Update README.md

* Update README_cn.md

* Update labelme2coco.py

* Update labelme2coco.py

* Update labelme2coco.py

* Update data_feed.py

* Including Fluid and Fluid-TensorRT inference time.