[Feature] Support FastFCN (#885)

* FastFCN first commit

* FastFCN first commit

* Fixing lint error

* Fixing lint error

* use for loop on JPU

* Use For Loop

* Refactor FastFCN

* FastFCN

* FastFCN

* temp

* Uploading models & logs (4x4)

* Fixing typos

* fix typos

* rename config

* change README.md

* use _delete_=True

* change configs

* change start_level to 0

* change start_level to 0

* jpu

* add unittest for start_level!=0