Fix sparse vars usage for dist train

polish sparse update code

Refine API doc string

Add document to random crop operator

Remove warning for rst file

Do not generate doc for op_role and op_attr_name

* fix dist train error

* update by comment

fix small bug in caculating speed

Infer multi-threads API Demo and UT

* "split into multiple .ccl"

* "refine file structure"

* "refine files"

* "remove the cmakelist"

* "fix typo"

* "fix typo"

* fix ci

fix bugs in the implementation of 'HasInput' and 'HasOutput'

Fluid benchmark support recordio reader

* "init benchmark ops"

* "untrack outputs"

* "delete some usused code"

* "benchmark"

* "fix ci"

* "fix op test"

* "fix uint16 missing"

* "fix ci"

* "follow comments"

* "fix ci"

* "follow comments"

* "conficts. merge develop branch"

* repick

* "merge develop branch"

* Add MKLDNN layout support in Paddle

Add MKLDNN layout in Paddle so that MKLDNN friendly memory layout
can be used in MKLDNN enabled OP kernel. Before this commit, NCHW
is hardcode to be used in all MKLDNN op kernels. As a result,
non-optimized execution path is selected in MKLDNN primitive which
bring worse performance.
Besides framework change, three MKLDNN OP kernels were updated
for using new MKLDNN layout. They are conv/pool2d/batch_norm.
Other MKLDNN OP kernels need be also updated in similar way to
achieve best performance.

* Add MKLDNN layout support in activation OP

* Don't populate layout from input to output when kMKLDNN in

* Refine pool mkldnn op kernel

* MKLDNN layout

* Remove the inferitance from tensor file

* MKLDNN layout: refactoring

* Remove additional #define to register new operator

* Prepare mkldnn tests to work with layout

fix a compile error on Mac

[Feature] Add fuse vars op handle

rewrite unittest of trt_activation_op

Add unittests to check channelwise add

Add reverse op