* fix div zero test=develop

* fix div zero test=develop

* add hostdevice function test=develop

* add eps when is zero test=develop

* don't expose numerous Tensor.set(), test=develop

* fix condition, test=develop

* fix float16 bug, test=develop

* feed should be Tensor or np.array, not Variable or number, test=develop

* use forcecast to copy numpy slice to new array, test=develop

* remove float16-uint16 hacking, test=develop

* add quant_dequant_moving_avg_max_abs op
test=develop

* add more note for quantdequant op
test=develop

* Add MovingAverageAbsMaxScale operator which is only used for calculating the quantization scale.

* test=develop

* change the output into inplace. test=develop

* Revert "test=develop"

This reverts commit 696cf62699ba1e1c98f61f7345ac7060010eb29a.

* Revert "change the output into inplace. test=develop"

This reverts commit a19acd20f07eee82622701a3015e6e9c073a5e0b.

* test=develop.

* update the MovingAverageAbsMaxScaleOp test. test=develop

* Add moving average absmax op in quantilize-aware training.

* Improve and fix fake_quantize_op.

* Add a fake_quantize_op, which quantize an input tensor to a tensor with lower bits.