This reverts commit a2a74a19.

* add skd distillation.

* update skd's test.

* support sub block

* support post-precess

* update

* fix

* add unittest

* revert prune

* fix unittest

* add unittest

1. Remove fluid
2. Remove unused codes
2.1 remove adabert
2.2 remove ddpg controller of NAS
2.3 remove paddleslim.models
2.4 Remove PC-DARTS

* optimization yaml

* update yaml

* update yaml

* fix unittest

* fix unittest

* fix distiller

* fix distiller

* fix distiller

* demo imagenet

* demo imagenet

* add source-free

* add source-free

* add asp

* update

* add fleet

* add docs

* rename

* fix unittest

quant aware with infer model

* fix dml issue

* disable multiprocess reader

* add other model

* add dml unittest

* fix log_softmax

* make dml compatible with 1.8 and 2.0 version paddle

* fix coverage