this is version 1.5.1

this is version lite-v0.1

this is version 1.5.0

this is version 1.4.1

this is version 1.4.0

Merge pull request PaddlePaddle#16457 from tianshuo78520a/change_cdn

test=release1.3

Fix the bug in fp16 backward kernel (PaddlePaddle#16266)

test=release/1.3

fix params with only 1 dim (PaddlePaddle#15828) (PaddlePaddle#15832)

* fix params with only 1 dim
* test=develop

Merge pull request PaddlePaddle#15251 from velconia/local_release_1_2_1

Refine MultiDevSSAGraph

Merge pull request PaddlePaddle#14773 from chengduoZH/fix_io_and_data…

…_feeder_doc

Fix io and data feeder doc