1.Remove the code for setting mkldnn environment in the test_calibration.py;
2.Update the cmake file for MKLDNN environment enabling;
3.Update the INT8 inference doc.
test=develop
* 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* Remove the outdated map operator which not supported on Python3.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
Wang, Chuanqi
Tao Luo
Zhang, Guoming
Dang Qingqing