* add roi pool

* rename input as x

* add dlpack api and fix a from_dlpack 

* fix paddle.summary's bug when output contains non-tensor

* add input option in model.summary

This reverts commit 6c110344.

* add num_iters in fit/evalate, test=develop

This reverts commit b2afc8df.

* update 2.0 public api in vision

* fix some flake8 errors

* fix Undefined variables

* fix Undefined variables

* add wget option in download

* fix retry in download when exception occurs

* add to_grayscale, normalize

* add rotate

* add vfip and hflip

* add crop center_crop


* add padding, support constant, reflect, replicate, circular same as paddle.pad

* add get-image-[n,c,w,h] axis utils

add __all__=[] to python files not in API public list; import * only support in API public list files (#32643)

* add op read_file and decode_jpeg

* Modified params of some APIs to support tuple and list.

* fixed bug.

* add Hub Module for easy to use pre-trained models.
*   support list, load, help fucntions.
*   support load models by github, gitee, local 
Co-authored-by: NLielinJiang <jianglielin@baidu.com>

* make hapi support amp, and add unittest

* make unittest only support GPU

* update parameters for amp in hapi.Model

* update hapi.Model.prepare interface, and update unittest

* fix test_model.py unittest bug

* add grad clear in dygraph

* use_fp16_guard defaults to True, which could avoid nan

* add input check, and add internal doc link to low level api

* update doc, and decrease the sample num of dataset to avoid timeout

* make hapi amp param  support str 'O1' or 'O2'

* resume calling , modify the code of the check part

* upgrade the usage of Fleet API, and disable 'pure_fp16' param

* fix warning and no grad

* fix cv2 rotation

* split callback unittest

* rm test_callback from timeout list

* fix DATA_HOME path in win

* add ReduceLROnPlateau

* enhance logger callback for benchmark