* fix the order of sum

* add doc

* check whether need to copy

* follow comments

* Simplify the travis script.
Now use docker to deploy documentations

* Check for the pull request

* Update paddle_build.sh

* Update paddle_build.sh

* api clean

* update API.spec

* "cherry picked cpp tests"

* "cherry picked"

* "cherry picked tests"

* "merge develop branch"

* "add gradient register"

* "make some enhance"

* "better format"

* "fix typo"

* "fix reuse"

* "fix get expected kernel"

* "change the mkldnn code"

* "fix mkldnn"

* "fix mkldnn failed test"

* "add comment"

Add a few more RecordEvent.
Cleanup

* Introduced by #11205

* "rewrite the test case"

* "follow comment"