Tuple Inputs&Outputs Support for ComputeOp

[ZihengJiang]

In order to implement some ops like argmax easily, we need to add multiple inputs support for ComputeOp, so that we can compare elements by their value with the index reserved.

• Tuple inputs&outputs support for normal ComputeOp
• Tuple inputs&outputs support for reduction ComputeOp

[tqchen]

#175