Fix export bug

Update det_basic_loss.py

keep postprocess params same

set dilation as False

优化部署、安装相关文档

fix are calc for polygon

Add new batch processing and undo functions

fix rare export error and support rare infer

fix srn for eval

Fix srn attn encoder for dygraph

polish code for srn eval

update rare dataset path

update readme and requirements.txt

Fix doc

to_variable has been removed in paddle 2.0,using to_tensor instead