test=develop

* Enable seq_pool op to accept len 0 input

test=develop

* Update sequence_pool's api

test=develop

* Add more unittest cases for seq_pool op

test=develop

* Remove legacy comments

test=develop

* Don't use template in op maker

test=develop

* fix regularizer lod bug; test=develop

* fix exception bug and one_hot expand; test=develop

* add reshape support tensor; test=develop

* fix reshape bug; test=develop

* change reshape attribute default value; test=develop

* fix reshape input name; test=develop

* fix reshape unitest; test=develop

* check dim tensor shape; test=develop

* refine doc for prelu

* update and polish hash op doc

test=develop

* update api spec

test=develop

* expand support tensor attribute; test=develop

* fix bug ; test=develop

* fix uni test bug; test=develop

* fix copy bug; test=develop

* refine expand_times default value; test=develop

* support some input tensor remain on cpu; test=develop

* fix input = none; test=develop

* fix unfound bug; test=develop

* fix proto None case; test=develop

* fix bug; test=develop

* fix proto null bug; test=develop

* remove conv check; test=develop

* fix test bug; test=develop

* move fill constant; test=develop

* no change in proto; test=develop

* fix bug; test=develop

* change attr detph name; test=develop

* remove remain cpu; test=develop

* fix bug; test=develop

* merge develop; test=develop

* fix one_hot bug; test=develop

* fix bug; test=develop

* fix bug; test=develop

* fix bug; test=develop

* fix python api bug; test=develop

* fix API examples of assign, reverse and array_write
test=develop

* update API.spec
test=develop

* update API examples for array_length, array_read, array_write, assign, hard_sigmoid, hsigmoid, increment, ones, pow, reverse, uniform_random and zeros

* update API.spec for assign, reverse and array_write, etc.(#17287)
* test=develop

* unit commits, test=develop

* update API.spec, test=develop

* API.spec test=develop

* update

* update test=develop

* update test=develop

* update

* update test=develop

* update test=develop

* update test=develop

* update test=develop

* update test=develop

* test=develop

* update

* update test=develop

* update test=develop

* fix:
1. infernce multi card occupy
2. facebox model inference occupy too much
test=develop

* refine python api comments: shuffle, while, scale, sampled_softmax_with_cross_entropy, scatter,
round, sin, sqrt, shape, split, soft_relu, slice, selu, ifelse, switch.
test=develodp

* fix conflict error.
test=develop

fix im2sequence padding bug

* update python APIs

test=document_preview test=develop

* update API.spec

test=document_preview

test=develop

* update merge_selected_rows

* update API.spec

test=document_preview

test=develop

* update API.spec

test=document_preview

test=develop

* fix the comment of less_than

test=develop

test=document_preview

* update API.spec

test=develop

test=document_preview

* update API.spec

test=develop

test=document_preview

* update API.spec

test=develop

test=document_preview

* update API.spec

test=develop

* update API

test=develop

* [DOC] Fix api docs, test=develop, test=document_preview

* [DOC] Fix api annotation: fluid.layers.tensor_array_to_tensor. test=develop, test=document_preview

* test=develop, test=document_preview

update MD5 of tensor_array_to_tensor

* fix unique_name growth bug in dygraph mode,test=develop

* change generate_tmp to generate_with_ignorable_key,test=develop

* fix example; test=develop

* fix api spec; test=develop

* fix api spec; test=develop

* add doc check
test=develop
test=document_preview

* test=develop,test=document_preview

add blank line to fix format, add one more "import"

* fix bug; test=develop

* fix bug; test=develop

* Fix the example code in some Python API.
test=develop

* Fix the example code in some Python API by adding import.
test=develop

* fix api example. test=develop

* fix API.spec. test=develop

* fix spectral_norm format. test=develpp

* merge develop

* add import. test=develop

* fix indent. test=develop

* fix indent. test=develop

* add import fluid. test=develop

* fix bpr data_norm teacher_student_sigmoid , test=develop test=document_preview

修复了bpr_loss data_norm teacher_student_sigmoid_loss三个api, 同时修复了continuous_value_model文档英文拼写错误

* fix api doc according to the reviewer's comment 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>

* test=develop

* test=develop

* test=develop

* test=develop
add sign op

* Update nn.py

test=develop
delete stop_gradient assignment

* Fix the example code in some Python API
* Update paddle/fluid/API.spec
* Fix some examples format

* test=develop
add elementwise_mod and elementwise_floordiv, fix equation problem in elementwise_mod

* modified formula for lrn

test=develop

* modified api.spec

test=develop

* fix API examples, test=develop

test=develop

* fix api doc of hash, relu, concat, argmin, argmax, argsoft and all activations funcs with no attrs

test=develop

* refine doc example code

test=develop

* remove >>> in doc example

test=develop

* refine python code block

test=develop

* update API spec

test=develop

* add attr axis infershape. test=develop

* add CUDA kernel. test=develop

* fix unittest. test=develop

* fix unittest for soft_label. test=develop

* fix fp16 unittest. test=develop

* remove comment code. test=develop

* refine test for axis. test=develop

* add python api. test=develop

* fix doc. test=develop

* fix fp16 unittest. test=develop

* fix ngraph test. test=develop

* fix ENFORCE for test_imperative_transformer. test=develop

* fit for ngraph test. test=develop

* fix after rebase develop. test=develop

* fix doc. test=develop

* fix API.spec. test=develop

* fix test_layers. test=develop

* fix format. test=develop

test=develop

* refine api comment, test=develop

* fix unexecutable API comments, test=develop

* add API.spec,test=develop