Fix fluid dist benchmark document errors

fix a bug of sub() in layer_math.py

* Adding set_capacity method support

* Adding Python for make_channel

* Updating notest_concurrency

* Write python for make_channel method

* Write python for make_channel method

* Fix make_channel and test

* Placeholder ops for channel send, recv and close

* Adding ToTypeIndex method to var_type.h

* Add var_type.h to channel:

* Added POD_Type to the method

* Add CHANNEL to executor

* Updated get and set DataType to accomodate Channels

* Updating get and set to incorporate channels

* Adding CHANNEL as supported VarType in protobuf

* Removing unecessary import

* Fixing VarDesc to adapt to Channel as VarType

* Add channel.h to executor

* Remove innclude from channel

* Updated var_type to support Channel as  var type

* Adding get_channel to pybind

* Added ChannelHolder

* Adding make_channel as an op

* Adding ChannelHolder in channel

* Fixing typo

* Commenting out operators in concurrency

* Removing totypeid right now since we don't need it.

* Reverting python changes

* Fixing typo in framework.py

* Modify comments for ReaderHolder

* Speed up elemwise grad

* Fix bug

* Add macro for MAX_BLOCK_DIM

Enhancement/transpiler rename grad vars to add trainer id, so RPC call can be retried.

small fix at macros

Add a script to bisect to a culprit commit.

Backward on parallel do using nccl

* Updating Var_desc.md with the updated typing system in Fluid

* Added Channel to VarType

Add Channel as a VarType

change outputsize func name

* Move Pod Types from DataType enum to Type enum

* Fixed data_type.h

* Fix type in TensorDesc

* Add comment to framework.proto

* Fixed type in data_type.h

* Updated format of type in data_type.h

* Fix var_desc.h

* Fix op_kernel_type.h

* Fixed data_type_transform_test.cc

* Fix operator.h

* Fixed data_type_transform.cc

* Fixed op_kernel_type_test.cc

* Fix operator.cc

* Fixed data_layout_transform_test.cc

* Fix var_desc.cc

* Fixed assign_value_op.cc

* Fixed assign_value_op.h

* fixed protobuf.cc

* Fix data_layout_transform_test.cc and op_kernel_type_test.cc

* Fixed rnn_memory_helper_op.cc

* Fix progrma_desc_test.cc

* Fixed fill_constant_batch_size_like_op.cc

* Fix operator_test.cc

* Fixed fill_constant_op.cc

* Fixed gaussian_random_op.cc

* Fixed uniform_random_op.cc

* Fixed edit_distance_op.cc

* Fixed fill_constant_batch_size_like_op.cc

* Fixed rnn_memory_helper_op.cc

* Fixed chunk_eval_op.cc

* Fixed assign_value_op.cc

* Fixed assign_value_op.h

* Fixed cast_op.h

* Fixed cast_op.h

* Fix fill constant op

* Fixed clang for assign_value_op.cc

* Fix one_hot_op.h

* Fix one_hot_op.cc

* Fix fill_op.cc

* Fixed sum_op.cc

* Fixed sum_op clang

* Fix uniform_random_op.cc

* Fix gaussian_random_op.cc

* Fix backward.cc

* Fix protobuf.cc

* Fixed prune_test.cc

* Fixed op_registry_test.cc

* Fix data_device_transform_test.cu

* Fix travis error

* Fixed one_hot_op.cu

* Fixed op_registry_test.cc

* Fixed nccl_op.cc

* Fixing python tests

* Revert "Fixing python tests"

This reverts commit fccaa4c5818ed9f379ea1ce4315066cc78076c64.

* Fixing Pybind to remove data type

* Fixing tensor.py

* Updated the new files:

* Resolve error in merge conflict of fill_constant_batch_size_like_op.cc

* Adding Python boilerplate code for Go op

* Add very basic test case

* Adding the python logic for go routine

* Fix syntax

* Changing test to notest

* Rename Routine to Go

* Combining GoGuard and Go in one class

* Modify test

* Adding fluid close channel

* Fixing __init__.py for calling fluid.go()

* Adding stubs for channel methods and updating test case

* Removing import *

* Adding imports from concurrency

* Support parallel test for understand_sentiment

* Full test on understand_sentiment

* Skip normal tests

* Debug CI

* Enable benchmark

* Revert init.cc

* Make CI pass

The type of tensor z should be bool. And there's no need to call mutable_data because ElementwiseComputeEx will do it.

* Generating random numbers with given batch size

uniform_random_batch_size_like_op
gaussian_random_batch_size_like_op

* More comments about random seed.

* Move test_*_random_batch_size_like_op to unittests

I expect that we need it to:
1. Find flaky test commit.
2. Find regression commit.
Disable test is dangerous. We should first try to find the culprit commit
and fix it or revert it.

I managed to find 3d1ac72a (between 279aa626 and 67731297) that causes
the recent failure of test_rnn_encoder_decoder.

design doc for parallel_do.md

* add python API for one_hot OP

* fix code style

* fix code style_2