* 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

* 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

* 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

* Tweak command line scripts

enable fine grained control of command flags parsing
switch to attribute style of accessing config options

* Break down visualization function

decouple it from IO operations

* Move flag parsing out of `main()`

* Fix a bug where `None` is returned instead of `{}`

* Rename `save_xxx` to `output_xxx` in command line flags

could be confusing since checkpoint is stored in `save_dir`

* Support image file extensions in upper case

* Fix `norm_decay` in config files

should be float value now

* Clean up a bit

mostly max line length related

* Fix ResNet18 and ResNet34 config.

* refine infer with args

* remove samples

* fix as review

* refine code

* refine args

* move get_test_images to infer.py

* add visualize log

* fix images = []

* fix args

* refine infer.py

* fix yolov3_r34.yml

* test=develop fix no random bug

May be problematic for unattended runs.

* Fix dtype for Yolov3.
* Clean unit testing.
* Add eval() for COCO-based algo.

* Merge setup.py and requirements.txt
* Fix cascade head initializer fanout

* Unified object detection framework based on PaddlePaddle.
* Include algo: Faster, Mask, FPN, Cascade, RetinaNet, Yolo v3, SSD.