* add stylegan2 and pixel2style2pixel models, predictors and documents

* add esrgan model, refine codes

* add animeganv2 network and dataset
* animegan:refine code,add License
Co-authored-by: Nqingqing01 <dangqingqing@baidu.com>

* Add Wav2Lip generator.

* fix auto downloading problem of dlib weight and add s3fd face detector

* add ugatit model

* fix import and docs

* Refine some docs
* Update docs/en_US/data_prepare.md

* refine code

* test

* fix apps

* update readme

* rm unused code

* fix apps output when input is image

* clean code

* update requirements.txt