Sophon

Major Features and Improvements
* Deploy on either SC3 or SE3;
* Replace some third-party libs to head only ones.
* Use new apis of BMNNSDK v1.1.3;
* Add samples for MXNnet and PyTorch models;
* Update documents by sphinx and abandon cpp document by doxygen;

Major Features
* Deploy on SC3;
* Integrate video decoder, image processing, NN inference, postprocessing;
* Provide both C++ and Python APIs, write inference application with short code;
* Automatically manage memory of tensors;
* Automatically split models from Tensorflow and Mxnet for BM1682;
* Provide algokit(a python algorithm toolkit) to deploy deep learning applications;