* fix -Wno-error=sign-compare warning in gcc8

test=develop

* fix warning in distributed codes

test=develop

* fix transpose conv,test=develop

* fix comments
test=develop

* refactor AUC OP and add its CUDA Kernel
* the layout of global auc doesn't change

There are PythonAPI tests in Op's unittest which don't need to inherit OpTest class.

* fix the device supported of the op unique and unique_with_counts.
test=develop
test=document_fix

* Fix the precision of test in the op of unique and unique_with_counts.
test=develop
test=document_fix

Add English doc for cond

* fix shape check in density_prior_box, test=develop

test=develop

test=develop

There are PythonAPI tests in Op's unittest which don't need to inherit OpTest class.

* add unused input vars check for OpWithKernel, test=develop

* remove unused vars in some ops, test=develop

* fix batch_norm, test=develop

* add white list, test=develop

* add CI check for white list, test=develop

* :ove white list to c++, test=develop

* solve failure of CI, test=develop

* add unittest for unused_var_check, test=develop

* refine code, enable check in operator_test, test=develop

* skip mkldnn, test=develop

* extend white list, test=develop

* refine condition of mkldnn, test=develop

* fix paddle_build, test=develop

* follow comments, test=develop

* fix GetExpectedKernelType

* add wiki ref to err_msg, test=develop

* follow comment, test=develop

* add param & grad shape check for sgd op

* add _reshape_inplece interface for dygraph parallel

* refine unittest based paddle/models scripts, test=develop

* add unittest for parallel grad fuse, test=develop

* Commit before merging develop

test=develop

* Backup after working with Huihuang logs

* Commit before deleting Huihuang debug loggings

* Commit before debug

test=develop

* Fix bug commit

test=develop

* Backup of fixing bugs

test=develop

* Clean up code

test=develop

* Fix a bug in sum_op

test=develop

* add selected rows support for debug string, test=develop

* refactor unittest of debug string, test=develop

* polish unittest name, test=develop

test=develop

test=develop

* Add ascending for argsort

* Refine api doc description.

* Refine descending description

* Add int32 logic to speedup when data is small size.

* Remove int32 opt as not support in python

* add_dygraph_execution_context

* add dygraph infershape context and execution context; test=develop

* fix imperative bug; test=develop

* remove inputs outputs interface from execution context,
because it have same function with inputNames;
test=develop

* remove tracer_test ctest; test=develop

* fix split op bug; test=develop

* fix unitests bug; test=develop

* fix distribute test bug; test=develop

* fix ngraph compile bug; test=develop

* fix grad maker bug; test=develop

* fix load op bugs; test=develop

* fix operator.cc construct bug; test=develop

* remove useless name find in operator; test=develop

* add tracer_test; test=develop

* fix concat, split bug; test=develop

* remove tracer_test unitest; test=develop

* fix attribute check bug; test=develop

* add test code to fix converage; test=develop

* remove useless code, change check backward input in engin; test=develop

* unlock var type infer shape;test=develop

* add ShareAllLoD api; test=develop

* add dygraph infershape context unitest; test=develop

* remove increase and decrease lod in dygraph; test=develop

* addd override; test=develop

* fix increase descrease lod; test=develop

* fix paddle_enforce; test=develop

* disable lod op dygraph check; test=develop

* fix paddle enforce error; test=develop

* add comment for op_registry and OperatorBase; test=develop

* optimize the comment of op_registry; test=develop

* fix format of comment; test=develop

* fix format of comment; test=develop

* optimize the format of comment; test=develop

* optimize the format of the comment; test=develop

* optimize comment of op_registry; test=develop

remove nccl related code in windows

* add Adam beta1/beta2 support Variable. test=develop

* use system allocator in unittests, test=develop

* fix op bugs, test=develop

* fix tensor copy bug when src and dst are the same, test=develop

* fix profile api high version test=develop

* batch_norm momentum support variable. test=develop

* fix format. test=develop

* add batch_norm momentum variable example. test=develop

* move MomentumTensor to training branch. test=develop

* split example. test=develop

* fix doc. test=develop

* fix PADDLE_ENFORCE ci. test=develop

* fix format. test=develop

* add ut for comparing FP32 and QAT INT8

* add save qat transformed model python script
test=develop

* updated

* added missing file

* add "with_label"
test=develop

* performance benchmark as unit test
test=develop

* change names of unnecessary thing

* Change CMakeList.txt for model downloading and UT
test=develop

* change names of functions and params for more readable code
test=develop

* Change PADDLE_ENFORCE messages
test=develop

* fix indent problems
test=develop

* indent problems
test=develop

* fix fleet save bug of save_infernece_model
* test=develop

* add lod information, test=develop

* add lod, test=develop

* fix lod, test=develop

* fix lod, test=develop

* remove -Wno-error=sign-compare, make warning as error

test=develop test=document_fix

* fix exist compile warning

test=develop