* fix inference on gpu out of mem

the transfer logic in operator.cc will keep creating new scopes.

test=develop

* add_infer_var_type
test=develop

* InferVarTypeHelper-> VarTypeInferenceHelper
test=develop

* PassInputTypeAndDTypeOnOutput
 test=develop

* follow comment
test=develop

* fix input<tensor>
test=develop

* fix split_ids
test=develop

* ElementwiseMul should not support SelectedRows

* fix scale op
test=develop

* change GetTensorFromVar() method to GetTensorOrSelectedRowsFromVar()

* fix operator

* refine MultiOutput

* fix MultiOutput
test=develop

* disable test_dist_save_load
test=develop

* fix elementwise_op
test=develop

* add get_sparse_as_op
test=develop

* add info for check
test=develop

* rename get_sparse_as_op with extract_rows_as_op.
test=develop

* elementwise doesn't support selected_rows

* fix regularizer

* remove extract_rows_as
test=develop

* fix ci
test=develop

* add test for sum_op

* fix regularizer
test=develop

*  test=develop

* fix pserver weight decay multi inputs test=develop

Fix code to support cpplint syntax check

test=develop

* fix GetTensorFromVar
test=release/1.1

* refine GetTensorFromVar
test=develop

* fix sum_op's GetExpectedKernelType
test=develop

* fix ci fail
test=develop

test=develop

* set the right shape of selected_rows
test=develop

* enhance check

* fix activation_op

* remove cast

* use ShareDimInfo replace SetDim and ShareLod

* use ShareDimAndLod
test=develop

* follow comment

test=develop

* check whether the input has lod
test=develop

* Split ShareDimAndLod

test=develop

* checkout clip.py
test=develop

test=develop

This reverts commit 21bb9e91, reversing
changes made to 3fa68dc1.

test=develop

- add naive executor
- fix concurrency performance issue

This reverts commit 1f270275.

This reverts commit b2df1700.

* Add Python Callstacks when Op::Run error

* Skip op with sub-block

* refactor: refine callstack info's format

* Reshape only support matrix

* Polish Python code

* Fix UT

* Fix Py3

* "cherry picked cpp tests"

* "cherry picked"

* "cherry picked tests"

* "merge develop branch"