* 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

* add dygraph parallel run interface

* polish implement & unified env property name

* add print config arg

* refactor init_parallel_env function

* Compatible with multiprocessing and launch modes

* set default trainer start port

* support run in python 2

* polish python2 support code

* remove python2 support

* refine launch import

* polish dome design details

* refactor api implemention & path

* use new method _set_expected_place

* add spawn unittest framework & mnist test

* add more unittests & doc

* fix unittest failed

* polish english doc

* self review and polish details

* refactor code by reviewer's comments

* fix unittest failed

* fix parallel_env unittest

* fix several typos

* fix error introduced when fixing typos

* add unpublic note for start_processes

* polish details by xiaoguang's comment

* verify correctly when spawn nprocs=-1

* refactor spawn & init_parallel_env design

* polish doc details

* open spawn unittests

* try to fix doc compile error

* try to fix unknown doc format error

* add skip unittest when not gpu

* update the demo code and the doc of varbase.backward.

* update the doc of the fake interface `paddle.fluid.Variable`.

* remove BackwardStrategy.

As the title

add the isnan, isfinite, isinf api for the paddle 2.0

* add bernoulli op

* fix cuda kernel and add unit test

* refine doc

* fix uniform

* Rename uniform and gaussian APIs

* rename uniform_random API as uniform

* Fixed unittest

* fixed unittest AttributeError

* Fixed unittest

* Add uniform function rather than alias

* remove templatedoc

* solve conflict and fix doc code

* fix doc code

* binding tensor method

* binding tensor method

* binding tensor method

* Binding methods for class Tensor and Variable

* Update `paddle.clamp`

rename to `paddle.clip`
add fast path for dygraph mode
remove `out`
rename `input` -> `x`
update doc sample

* Fix leftover `Variable` wording

* Indent doc with spaces

* Remove `:alias` in docs

* Update `enable_imperative` -> `disable_static`

* Remove `imperative`

also trigger CI

* Update tests for better coverage

* Rebase to fix `cosine_similarity`

* Fix `cosine_similarity` some more

* fixed static module

* solve conflict

* Add Distribution base class, Uniform class and Normal class

* release Distribution class and Normal, Uniform class

* Add Doc args explaination

* save distributions.py and process in distribution.py

* delete useless function in test_distribution

* Add NormalNumpy test class

* Add probs in NormalNumpy

* add distribution to paddle init

* Add Distribution base class and name attribute unittest

* Change Doc

* Change Doc

* adjust format

* Fixed Doc Code

* implement probs and change Variable to Tensor

* Add name for all functions and add name unittest

* support int datatype

* Add dynamic mode

* optimize test_distribution static and dygraph

* Add new API: paddle.prod

test=develop

align expand_as op to expand.

* add set/get default dtype

* expose and unify the Tensor concepts to the user

* expose tensor to user

* add copy place for Tensor

* add copy place for Tensor

* add note

* add macro PADDLE_WITH_CUDA

* remove RUN_TYPE=DIST

* fix some error

* add tile_op, test=develop

* Upgrade `no_grad` decorator

test=develop

- match torch decorator usage (i.e., with parenthesis)
- handle generator functions
- add `paddle.no_grad` alias

* Switch from `functools` to `decorator`

preserves signature

* Reword decorator usage note

* fixed static module

* solve conflict

* remove original name for alias API

* move paddle.fleet to paddle.distributed.fleet

* Add the max, min, maximum, minimum api for the API 2.0, test=develop

* Directory migration, test=develop

* Change imperative from paddle init to paddle framework, test=develop

* Fixed jit bug, test=develop

* default static mode, test=develop

* fixed format and create parameter belongs to framework, test=develop

* Fixed import package, test=develop

* fix __init__ format, test=develop

* fixed alias problem

* fixed paddle.enable_imperative problems, test=develop

* Add unittest

* delete install_check comment

* Fixed unittest timeout

* fixed unittest error

* move Program default_xx_program to static package

* optimize unittest method

* fixed framework __init__ format

* fixed jit path

* delete alias

* move jit to paddle

* Fixed unittest format

* fixed paddle.default_main_program

* Fixed save load API in paddle __init__.py

* fixed ci paddle.imperative.to_variable

Update the code for the compare_ops, update the api and doc 

* New features, add sinh and cosh op, test=develop

* remove duplicate test function and remove out paramters, test=develop

* Add out paramters temporary, remove later. test=develop

* remove out args, PR 25570, test=develop

* remove TestParameter, test=developx

* add test api for static dygraph, test=develop

* add backword unittests for sinh and cosh, test=develop

* add op multiply, delete op elementwise_mul from math.py. test=develop,test=document_fix

* bug fix. test=develop,test=document_fix

* bug fix. test=develop,test=document_fix

* bug fix. test=develop,test=document_fix

* bug fix. test=develop,test=document_fix

* add unittest for multiply op. test=develop.

* fix code style. test=develop

* use random input. test=develop

* add test error case for static computation graph. test=develop

* add np.random.seed(7)

* increase input ndarray size. test=develop

* change float32 to float64. test=develop

* delete mul op. test=develop,test=document_fix

* bug fix. test=develop,test=document_fix

According to paddle 2.0 standard
1, change flip api attr name 'dim' to 'axis'.
2, support empty axis
3, change example code to imperative mode.

* add paddle.fleet.DistributedStrategy for 2.0

* add histc operator, test=develop

* update english doc to 2.0 API, test=develop

* update API from histc to histogram, test=develop
Co-authored-by: Nroot <root@yq01-gpu-255-129-15-00.epc.baidu.com>

* add alias in paddle.nn and paddle.tensor test=develop

* add alias in paddle.nn and paddle.tensor dir test=develop

* fix same conflict manually test=develop

* update fc and dygraph alias test=develop

* fix initalizer.py typo test=develop

* add base name alias; test=develop

* fix embedding bug; test=develop

* fix io error; test=develop

* add metric; test=develop

* add import palce; test=develop

* add setup; test=develop

* fix incubate reader; test=develop

* fix initializer error; test=develop

* Merge hapi into Paddle

Hapi is a high level API for training and inference.
The main modules include Model, Loss, Metrics, Dataset.
Also includes common modules and models in NLP and computer vision, such as BERT, ResNet.

These modules are developed by:
0YuanZhang0, guoshengCS heavengate, LielinJiang, qingqing01, xyzhou-puck huangjun12, wangxiao1021, zhangyang.

* copy dygraph api to paddle.imperative, test=develop

* polish the code, test=develop

* polish code, test=develop

* polish code, test=develop

* move paddle.imperative.Layer to paddle.nn.Layer, test=develop

* Move complex into dir incubate, test=develop

* Fix imports, test=develop

* Fix docs, test=develop

* Forbid import functions from paddle.incubate directly, test=develop