* upgrade collective fleet api

* fix transform matrix bug, test=develop

* modify API.spec

* add random port

* Fix topk cannot handle 1D vector bug

Add path to handle 1D vector

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

* refine code

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

* test=develop, fix docker with paddle nccl problem

* test=develop, hide no_support api and add ut for it

* add_distributions_of_normal_and_uniform

* paddle/fluid/API.spec

* modify API.spec

* modified paddle/fluid/API.spec, test=develop

* modify paddle/fluid/API.spec, test=develop

* modify paddle/fluid/API.spec, test=develop

* fix some comment, test=develop

* modify API.spec, test=develop

* add comment for init function, modify hard code, test=develop

* modify API.spec, test=develop

* modify API.spec, test=develop

* make unit test function shorter, test=develop

* modify paddle/fluid/API.spec

remove pycpuinfo deps in core

* make it support float/int learning as input.

* enhance execution error info
test=develop

test=develop

* test=develop
support Tensor input for chunk_eval op

* test=develop
fix testcase for chunk_eval op

* test=develop
fix typos in nn.py

move the thread-check code from train_from_dataset to a single function
add UT for the thread check function

1. Since allreduce op has 4 reduce types, We split these four reduce types into four ops
2. We also refined the collective op code, e.g. we separated the collective op kernel into CPUKernel and CUDAKernel, and remove the device specified DeviceContext parameter in template as we already knew the target DeviceContext
3. We remove the newly added Collective op role to reduce the complexity of program and graph analysis

make fleet support mpi job submit directly.

* add not_been_used_vars to no_grad_set
test=develop

* modify roi_perspective_transform_op to output mask and transform matrix

* modify comment

* modify comment

* modify API.spec

* update API.spec

* remove no use header, test=develop

* resolve conflict

* fix mac ci random fail
* use platform instead

replace mnist dataset url

* update api format
test=develop

* update API.spec
test=develop

* fix py-cpuinfo mac random fail
* differentiate version on windows

test=develop

* add MultiSlotStringDataGenerator for speedup of string based user input data

* test=develop, add some comments for Program.clone

* test=develop, add API.spec

* test=develop, refine comments

* refine Program doc and clone doc

* test=develop, refine doc

*  add cuda_is_available
test=develop

* Fix api.spec
test=develop

* fix api doc
test=develop

test=develop

Fix dygraph show style for FluidDoc.

* update pe reduce config
test=develop

*  drop the local_exe_scopes of the previous parallel_executor
test=develop

* add is_runnning in communicator, test=develop