* add quant_dequant_pass, test=develop

* Add quant_dequant before some ops, such as the elementwise_add op. This is required by TensorRT. test=develop

* Add LAMB optimizer

* Expose LAMB Optimizer's APIs

test=develop, test=document_preview

* Cleanup code & doc

test=develop, test=document_preview

* Update lamb optimizer's formula

test=develop

test=develop

* Add api doc code examples

add or fix topk, squeeze, stack, StaticRNN,
StaticRNN memory in doc

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Add squeeze md5.

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Add import package

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Add 6 models tests support in CMake

* enabling resnet101, vgg16, vgg19 INT8v2 model tests
test=develop

* remove SERIAL
test=develop

http://newicafe.baidu.com:80/issue/PaddleSec-33/show?from=page
http://newicafe.baidu.com:80/issue/PaddleSec-28/show?from=page
http://newicafe.baidu.com:80/issue/PaddleSec-25/show?from=page
http://newicafe.baidu.com:80/issue/PaddleSec-24/show?from=page
http://newicafe.baidu.com:80/issue/PaddleSec-21/show?from=page
http://newicafe.baidu.com:80/issue/PaddleSec-20/show?from=page

test=develop

* add quant_dequant_moving_avg_max_abs op
test=develop

* add more note for quantdequant op
test=develop

* optimize communicator flag

* change flags in init py test=develop

* improve the doc of paddle.fluid.memory_optimize, test=develop

* fix typo, test=develop

test=develop

* fix the random compilation failure on windows 

* double backward, elementwise_div

* fix dx empty. test=develop

* bug fix (#17392)

fix secure bug

* Eanble stack operator for a Ngraph, test=develop (#17406)

* fix sqrt_grad_grad unittest. test=develop (#17410)

* fix sqrt_grad_grad unittest. test=develop

* disable sqrt_grad_grad unittest. test=develop

* test=develop, fix unittest

* test=develop, fix unittest

* test=develop, fix unittest

* test=develop, fix bug

* fix unittest. test=develop

* fix unittest dx. test=develop

* tmp fix! for test... test=develop

* reduce tmp, test=develop

* test=develop, reduce tmp

* fix broadcast unittest. test=develop

* fix format. test=develop

* refine code. test=develop

* refine code. test=develop

* refine GetDoubleGradSafeTensor. test=develop

* fix format. test=develop

test=develop

add elementwise_sub_grad_grad op for backward of backward calculation

* fix data_feed_desc.py example run error
test=develop
test=test=document_preview

* fix data_feed_desc.py example display error
test=develop
test=document_preview

* update API.spec for DataFeedDesc
test=develop
test=document_preview

* examples use code-block in dataset.py
test=develop
test=document_preview

* add QueueDataset example
test=develop
test=document_preview

* add record_event
test=develop

* remove csp
test=develop

test=develop

* add var grad hook test=develop

* test=develop, add gradient sort backward strategy

* test=develop, fix test by add FLAGS_cudnn_deterministic on new tests

* test=develop, fix memory leak in dygraph mode

* test=develop, fix memory leak in dygraph mode

* test=develop, polish code

* test=develop, polish code

* test=develop, polish code

* add cache_update_mutex_ for operator 

* improve gru unit performance.
refine code

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* Add conditional compile for gru opt

Not enable gru opt if compute ability < 700

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* refine code.

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* improve the API Sample of DataFeeder, memory_optimize and release_memory, test=develop

* update API.spec, test=develop, test=document_preview

* tweak the code format of feed API, test=develop

*  update API.spec, test=develop

* improve doc for DataFeeder and default_main_program, test=develop

add inductive shape index

This reverts commit aca60e9a.

Refine the Executor when the num_thread=1

* init auto loss scaling

test=develop

* change API.spec

* change ifelse to switch and use reduce_sum to optimize checking isfinite

test=develop

* Remove redundant code

test=develop

* add set_not_owned function for graph

* add scope set. test=develop

* add scope_ptr enforce not null before setting.test=develop