* refactor rcnn, test=dygraph

* add mask_rcnn, test=dygraph

* add Faster RCNN & Faster FPN, test=dygraph

* update according to the review, test=dygraph

Merge dygraph branch into master branch.
Co-authored-by: NFDInSky <48318485+FDInSky@users.noreply.github.com>
Co-authored-by: Nsunxl1988 <47514455+sunxl1988@users.noreply.github.com>
Co-authored-by: Nwangguanzhong <jerrywgz@126.com>
Co-authored-by: Nwangxinxin08 <69842442+wangxinxin08@users.noreply.github.com>
Co-authored-by: Nwanghuancoder <wanghuancoder@163.com>
Co-authored-by: Ncnn <liuhui29@baidu.com>
Co-authored-by: NGuanghua Yu <742925032@qq.com>
Co-authored-by: NKaipeng Deng <dengkaipeng@baidu.com>
Co-authored-by: Nroot <root@bjyz-sys-gpu-kongming0.bjyz.baidu.com>

* deploy/cpp : Update cpp ineference solution

* add README.md to deploy

* deploy/cpp : add PadStride

* deploy/cpp : add output visualization

* deploy/cpp: add video support

* fix coding style problem

* deploy/cpp : add README.md

* deploy/cpp : update docs

* deploy/cpp : update linux build scripts

* deploy/cpp : update linux build docs

* udpate docs

* deploy/cpp : update windows build docs

* depoy/cpp: fix coding style

* fix coding style

* Create CMakeSettings.json

* Update README.md

* Update windows_vs2019_build.md

* Update CMakeLists.txt

* Update linux_build.md

* Update CMakeLists.txt

* deploy/cpp : update linux build script

* update doc structures and support arch Face