* Impl fp16 compute kernel for slice_op

* Use data() to replace mutable_data()

test=release/1.3

Fix release/1.3 Executor doc

test=release/1.3

cherry-pick pool/adaptive_pool/yolov3_loss doc fix

test=release/1.3

* fix params with only 1 dim
* test=develop

* fix group_norm (#15727)

* update fast install shell

* test=develop, enhance mac fast install

* fix pip Failure due to too low version;Add python virtualenv

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

Revert "Cherry pick/update protobuf"

test=release/1.3, fix patchelf install for python3.5

This reverts commit 08a8c1d1.

* test=develop, change md5 for patchELF

* test=develop, update protobuf

* test=develop, update protobuf in Dockerfile used by CI

* test=develop, install requirements before start for Linux

* test=develop, uninstall protobuf on linux brefore install latest version of it

* test=develop, fix pip

* test=develop, install protobuf in linux

* test=develop, fix patch ELF install failed

* test=develop, change md5 for patchELF

* test=release/1.3, cherry-pick

test=release/1.3

Fix doc

Fix FtrlOptimizer's API comment

cherry-pick memory optimize changes to release

cherry-pick/Fix batch_norm API for data_layout.

cherry-pick/Fix debug mode in prior_box_op (#15702)

merge security issue fix test=release/1.3

test=release/1.3

test=release/1.3

Removed duplicated code

test=release/1.3

test=release/1.3

test=release/1.3

[cherry-pick] [V1.3] resolve #15724 

Fix lstm possible leak

test=release/1.3

cherry-pick/Fix row_conv doc

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=release/1.3

Cherry-pick signature error to Release/1.3

cherry picked. test=develop

cherry-pick/Fix debug mode in fake_quantize_op (#15693)