* Add the calibration tool code for int8 inference and focus test.

* Fix the calibration tool per the review comments.

test=develop

* Update the calibrator doc and remove extra line.

* Fix the invalid is_negative_input attr set on Mobilenet.

* Add the comments and fix the format issue.

test=develop

* Update the CMakelist.txt for Calibration PR.Disable the Calibration UT if not enable MKLDNN.

test=develop

* Update the CMakeList.txt.

test=develop

* Disable the test_calibration case on WIN and MAC.

test=develop

* Add the missing brackets.

test=develop

* Remove the outdated map operator which not supported on Python3.

test=develop

* Fix the style issue.

test=develop

* 1.Update the CMakeList.txt to disable calibration tool ut when the WITH_MKL is not set;
2.Add the workaround to enable the FLAGS_use_mkldnn for PR_CI(PADDLE).

test=develop

* Fix the typo and format the License header.

test=develop

* 1.Add and Update TODOs per review comments.
2.Code clean.

test=develop

fix trt stream bug.

checkpoint for distributed training.

test=develop

* Add generate_mask_labels_op to support Mask-RCNN.
* Refine sigmoid_cross_entropy to support nomalize mode.
* Fix generator_proposals_label.
* Use DeviceTemporaryAllocator in roi_pool and roi_algin.
* Remove shape check in data_feeder.

* Add check of input in sequence_expand op.
test=develop

* Correct the unittest of sequence_expand op.
test=develop

Graph quantization pass. TODO(Add public API comments.)

remove legacy compiler option

* remove workspace_handle
test=develop

* set constant for loss
test=develop

fix test_word2vec float's equality bug

test=develop

test=develop

test=develop

tweak the executor implementation to better match origin behavior

BUG: After continuing to input different data, the output cannot be aligned
test=develop

fix pr 15313

test=develop

test=develop

add python inference api

test=develop

test=develop

test=develop

fix the prompt when dll load failed on windows