* refine paddle.stack

* support TensorArray

* add test

* fix coverage problem

* fix coverage problem

* fix sample code

Fix some code samples in Tranoformer apis.
test=develop

* fix dropout bug in backward when input is 1d tensor, test=develop

* add test case and refine error message, test=develop

* refine error message, test=develop

* set_default_type only take effect on python floats or complex

* fix doc

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* fix norm bug, test=develop

* replace fluid.optimizer.set_dict with optimizer.set_state_dict

* replace fluid.optimizer.set_dict with optimizer.set_state_dict

* add coverage rate

* Increase coverage rate, fix code style

* Increase coverage rate, fix code style

* add fit to generate optimizer.state_dict() to save .pdopt to increase coverage rate

* delete http.log

fix pool trt plugin bug
test=release/2.0-beta

* fix sample codes, test=develop

* fix fluid.embedding

* add embedding 2.0

* add embedding support input int32

* add check for bernoulli and register bool for unsqueeze

* follow comments

[CI] Change RD for check_op_desc from (liym27, zhhsplendid, Aurelius84, lanxianghit or phlrain) to (cyj1986, Superjomn) (#26828)

* turn on WITH_INFERENCE_API_TEST

* Count the time and packet size on windows

* fix conflit

* fix conflit

* fix conflit

* fix date-time funciton

* remove backend argument of init_parallel_env

* remove keep name table in transformer

* add cpu version check

* add skip unittest for init_parallel_env

* polish doc: remove func use & update example

* add FleetAPI doc
Co-authored-by: Nliuyuhui <liuyuhui@baidu.com>

rename Dropout2D/3D to Dropout2d/3d

* refine cudnn softmax

* get use of global 'use_mkldnn' in layer_helper

* update for CI

* update for CI, relu test

* update for CI, relu test added, make FLAGS_use_mkldnn a public flag

* added more strict tests, fixes after review

* fixes after review

* fixes after review, CI stuff

* support trt dynamic shape int8

* add unittest

* add support for sigmoid; adapt to trt6+ api

* Fix Python Version compatibility

* add import six

fix doc, use to_tensor for the loss ops

update the doc for the some ops, ceil asin, atan

* Move hapi form paddle/incubate to paddle

* Remove vision/datasets/utils.py and clean code

* Add sample code for conll05

* Print pull path when saving model

* Fix sample code after paramter_list of SGD is changed to parameters

* Fix bug in wmt16 datase

* set default dtype for distribution API

* Add unittest

* Add unittest

* fix import get_default_dtype problem

* delete change under fluid.layers.nn

* little change

* Support Heter Parameter Server