In this way we can build and test using WITH_FLUID_ONLY flag being set
to ON.

- move paddle.v2.dataset,reader to paddle.dataset,reader
- remove unused code (which depends on v2) in paddle.dataset,reader

* 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 fetch record from master

* using etcd as fault tolerant training

* update

* workable version, ft not tested

* small fix

* update

* remove TODO

cluster dataset split and reader