init mnist

register rowwise add gpu kernel

master client: retry connecting to etcd

Feature/minus op

reduce some compile warning

Add a sequence slice layer.

Move pybind from package paddle/framework into paddle/pybind.

Identity operator and its gradient

Feature/extract op info into op info.cc

enable layer group to output a sequence inside it during generation.

Correctly handle width and height for DataLayer and ScatterAgentLayer.

Gather_op with python op passed