Refine listen and serve op

* Revert "accelerate dropout (#9902)"

This reverts commit 2e331c65.

* Correct discard

Fix scope of gather and broadcast, and code clean

fix reduce_op_handle_test

make for_parallel default True

"polish activation"

Add flush of program desc to update the proto information.

Feature/add reduce op handle

Refine gather and broadcast

Eager destruct local scope

VariableResponse support deserialize var into local scope

* Fix print op cpplint errors

* Remove commented code

fix split byref op mac build

Skip updating not trainable parameters in distribute transpiler

Remove intermediate output's gradient from inputs of grad_op.

check pserver file while writing dockerfile