* remove SliceCopied

* remove SliceCopied

* rename SliceShared to SliceLevels, SliceInLevel

* merge lod_tensor/details

* remove lod_start_pos_'s shared_ptr

* make lod-tensor a special tensor

* add clone to lod_tensor

* add lod tensor impl

* add lodtensor clone test

* init lod

* add equal

* merge LOD and its methods

* recover tensor and variable

* change thrust to host_vector

auto update the requirements in .travis.yml with python/setup.py.in

fix cpplint error

add auto gradient check design doc

remove eigen tensor header file in ddim.h

Refactorize grad op builder.cc

Correct the use of protobuf generated methods

Merge branch 'develop' of https://github.com/paddlepaddle/paddle into refactorize_grad_op_builder.cc

Add constructors to OperatorBase and all sub-classes

Refactorize registry macro

Add OperatorBase accessors

Remove FC Op, since it should be added in Python side
Fix #3418

Fix save large parameters crashed

Refine the unit test of convolution function.

Fix compile on develop branch

delete useless codes in softmax backward.

* golang pserver optimizer config for user

* update

* update

* update

* update

* update by comments

* fix errors

* fix errors

Switch from GCC 5 that doesn't work with Eigen to 4.8