Add deep clean script
添加深度清理脚本

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Merge branch 'sources' into projects

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Deep clean project directory
深度清理项目目录

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Merge branch 'projects' into dev-2

Conflicts:
	project/preprocess.bat

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>