* update model save load

* first add

* update model save and load

* update train.py

* update LaneNet model saving and loading

* adapt slim to paddle-1.8

* update distillation save and load

* update nas model save and load

* update model load op

* update utils.py

* update load_model_utils.py

* update model saving and loading

* update copyright

* update palette.py

Co-authored-by: Nchenguowei01 <chenguowei01@baidu.com>