Update api.rst (merge to develop)

* elementwise_add with bcast: Brian's implementation by Brian added, with default bcasts

* elementwise_add with bcast: GetExpectedKernelType added to elementwise_op

* elementwise_add with bcast: use_mkldnn attribute added

* elementwise_add with bcast: changes after review and some formatting

* elementwise_add with bcast: changes after style check

* elementwise_add with bcast: changes after style check cont.

* elementwise_add with bcast: MKLDNN unittests added

* elementwise_add with bcast: original unittests with use_mkldnn flag

* elementwise_add with bcast: handling of MKLDNN format corrected

* elementwise_add with bcast: setting MKLDNN format turned into lambda

* elementwise_add with bcast: MKDNN format setting turned into separate function

* elementwise_add with bcast: condition for choosing MKLDNN simplified

* elementwise_add with bcast: fix for MKLDNN format set incorrectly in bcasts

* elementwise_add with bcast: changes in unittests for broadcasts

* elementwise_add with bcast: fixes in unittests regarding dimensions

* elementwise_add with bcast: bring back correct format setting in mklml grad path

* elementwise_add with bcast: fixed compilation error

fix sparse paraexe dist train

fix metrics.Auc

Some small fixes

Small doc fix and clean up of reshape

* Fix relu and log

* Update nn.py

* make deadline configurable

* configurable deadline

* update

* fix grpc deadline exceeded

anakin build adapt

fix pserver sub-blocks

* Make paddle no longer depend on boost

* Update enforce.h

MKLDNN: SoftmaxGrad Op

add example of clone(for_test)

added cycling the cifar and flowers datasets

* 1. Remove PYTHON_FLAGS from paddle_build.sh in paddlepaddle/paddle:latest-dev

* 1. Add PYTHON_FLAGS back
2. Change SIGKILL to SIGINT and SIGTERM

* 1. Add setup.py.in back

* 1. add pip install open-cv in Dockerfile to avoid libusb_exit hanging up which is caused by the opencv-python package missing

* 1. Add the && \ to line above

* 1. Remove the notice comment

fix mac compile

Fix log and relu layer

Add FAQ[libmkldnn.so.0 is not found when importing paddle.fluid]

cherry-pick: fix indentation error

- Added hash function inside of MKLDNN softmax op to be used as handle for primitives stroing in a
context

- Style fixes to softmax mkldnn op

- Fixes after review

- Coding style

- Fix to style

- style fixes

- style fix

- style fixes

- Fix to cody style check

- Rephrasing a comment

fix t obroken merge

Fixes to rebase

Conflicts:
	benchmark/fluid/models/machine_translation.py
	cmake/external/mkldnn.cmake
	paddle/fluid/operators/softmax_mkldnn_op.cc

- Bumped revision of MKL-DNN up to have softmax backward primitive

- Added choosing MKLDNN softmax grad operator

- First reuse of softmax backward

- Reinvented reusing for softmax

- Fix to crash in reinvented reuse

- Clang format fixes

- Clang format fixes

- Improved softmax mkldnn reuse mechanism

- clang format fixes

- Fix to broken merge

- Fix