* refine ptq according comments
* reuse the module to calculate kl threshold

* add amp support for pp

* add amp untest

* fix hdfs and fleet_util for supporting save/load infer;test=develop

* enhance error message when x or y is empty in elementwise_op

* format code

* format code

1. check status of remove op grad shell scripts
2. Update paddle_build.bat to remove op grad when build windows inference lib
3. add inference demo test after build finish

* Save all scales to target ops
* Move quant layers to paddle.nn.quant

* delete useless GELU in gelu npu op

* add description

* fix format

* add check_grad in gelu unittest

* refine the old code

* support moving_average_abs_max and per_channel_abs_max

* Add moving_average_abs_max_scale op

* Convert the test program

* add random and prevent deadlock

* fix safe bug of scatter/scatter_nd

* dygraph sharding

* update unitest hybrid_parallel_communicate_group

* add get and set for Grad_scaler

* refine some API name and comments

* refine API name and comments

* refine some comments