* 1. fix build errors when install gnu commands in MacOS
2. add a script to fix license-header
Signed-off-by: Fansong Zeng <fanster.z@gmail.com>

* use perl instead of sed for compatibility
Signed-off-by: Fansong Zeng <fanster.z@gmail.com>

* fix license header
Signed-off-by: Fansong Zeng <fanster.z@gmail.com>