fix dropout and clipping settings in layer helpers.

Fix bug for multi-GPU inference.

* fix recordio split and task passes

* update for pre commit

* update

* update, still need to sync client wait for pass end.

* able to sync passes for task dispatching

* update to comment

* update

* fix yapf check

* why local pre-commit fails? version is the same

* fix race condition

* update

* fix race condition

* this still have duplicate problem in unit test

* update

* update

* update by comment

* update

fix bug in OpKernel register macro

ENH:  for clarity, change DLOG to VLOG