* test=develop
The scatter op has a calc bug when the indices has same index, the scatter op use overwrite mode to calculate the same index, fix this bug by using the accumulate mode to calculate the same index.At the same time, the gather op has the same bug when the op calc the grad. And we use the lib of open-blas and eigen to optimize the time cost in accumulate mode.
* test=develop
Fix some code format problem, and the same time add the test case in gather and scatter op
* Refine beam_search_op to output an extra parent_idx tensor.
test=develop
* Fix the unittest test_beam_search_op.
test=develop
* Fix the merging mistake.
test=develop