* Rename folder name in PaddleCV
* rename PaddleVideo to video
* rename PaddleGAN to gan
* rename Paddle3D to 3d_vision
* remove PaddleSlim

* Add PaddleDetection/release/0.2 as submodule

* Update link in models/README.md and models/PaddleCV/README.md

* remove yolov3, ssd, rcnn and PaddleDetection.
* remove ICNet, deeplabv3+.
* remove Research
* remove empty folder.

* fix test and infer for ctcn

* add instruction to dataset/ctcn/readme

* Add ctcn model for action detection

* remove data list from codebase

* test=develop fix error while loading cv2.VideoCapture

* test=develop
fix bug of index out of range in SampleFrames

* fix bug

* add tsm ce

* add tsm ce

* add enable_ce in configs

* remove enable_ce in val config

this is for issue #2232
add pretrain description in readme to show that some models need pertained models to begin training.

* fix video train param name epoch.

* fix for script.

* fix subprocess not stopping bug

* term -> _term

* fix video get learning_rate error

* refine comment