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

* This PR adds broadcast for multi-process. And it could be used in dynamic graph to broadcast parameters.

Python examples of fluid.layers.io.double_buffer and some BuildStrategy's methods.

* add conv_concat_relu fuse

test=develop

* add test code

test=develop

* added missing include with unordered_map

test=develop

* review fixes for wojtuss

test=develop

* remove 'should (not) be fused' comment statements

one of them was invalid anyway

test=develop

* fix quantize_squash_pass segfault when there is no tensor linked do Bias input

test=develop

* add googlenet test

test=develop

* fix concat CreateKey not using input format

test=develop

* add profiler in tracer.cc

* add profiler in layer.cc
test=develop

* add profiler in Layer.cc
test=develop

* test=develop

* test=develop

* test=develop

* del #

*  Enable assign operator for a ngraph, test=develop

* Cross_entropy operators needs to be updated

* polish_executor_and_add_ctx_cache

* refine softmax fwd

test=develop

* refine cpu softmax bwd

test=develop

* fix batch size

test=develop

* fix compile issue with gpu

test=develop

* add value clip

test=develop

* Add exponential moving average

test=develop, test=document_preview

* Polish documents

test=develop, test=document_preview

* Update API spec

test=develop, test=document_preview

* refine softmax fwd

test=develop

* fix compile issue wih gpu

test=develop

* add value clip to avoid exp

* Revert "Revert "Fix allocator bug""

This reverts commit 174d0d0b.

* Revert "fix travis ci"

This reverts commit 5656fa9f.

test=develop

* add inlined_vector.h, test=develop

* add inlined_vector_test,test=develop

* test=develop

* 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 distribute doc

* fix concat op vartype check, test=develop

Async exe support communicator

ban all trt ut. will fix it later.

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

* test=develop

* test=develop

* modify saved model path in analyzer_save_model.cc test=develop

test=develop

* test=develop, fix con2d with no bias

* test=develop, fix conv_2d with no bias will have null shape

* add increment op to ngraph engine

test=develop

* fix style errors

test=develop

* Fix examples of fluid.layers.sums.
test=document_preview

* Correct the example of DynamicRNN and its functions.
test=develop

* Add 'import paddle.fluid as fluid' to examples.
test=develop

* Update API.spec.
test=develop

* Add space lines.
test=develop

* Update the API.spec.
test=develop

* Relu6 is the bottleneck op for Mobilenet-v2. As the mkldnn supports the conv/relu6 fusion, we implement it fusion via cpass way. Due to the int8 enabling for this fusion will be supported in MKLDNN v0.20, so this PR is focused on the fp32 optimization.

Below table shows the benchmark(FPS) which measured on skx-8180(28 cores)
Batch size | with fusion | without fusion
-- | -- | --
1 | 214.7 | 53.4
50 | 1219.727 | 137.280

test=develop

* Fix the format issue

test=develop

* Add the missing nolint comments.

test=develop

* Fix the typos.

test=develop

* Register the conv_brelu_mkldnn_fuse_pass for the MKLDNN engine.

test=develop

* Adjust the indentation.

test=develop

* Add the test_conv_brelu_mkldnn_fuse_pass case.

test=develop

* Slightly update the code per Baidu comments.
Let the parameter definition embedded into the code.
That's will make the code easy to understand.

test=develop