* add stylegan2 and pixel2style2pixel models, predictors and documents

* set en readme as default

* Add MidDaSv2 in ppgan.apps
* remove ppgan/apps/midas/run.py

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

* add ugatit model

* refine codes docs

* fix pix2pix to_tensor

* fix apps

* refine duplicate frames and fix some bugs

* add face_parse predictor in apps

* remove duplicate frames and keep timestamp, fix psgan docs

* add art model of deoldify

* update demo

* update psgan pretrained model link in the tutorial doc

* refine codes docs

* Add doc for Apps and refine some code
* Add how to switch cpu and gpu

* refine code

* test

* fix apps

* update readme

* rm unused code

* fix apps output when input is image

* clean code

* update requirements.txt