onnxruntime

Quantization tool to support quantization of Conv and MatMul nodes. (#1057)

* Move quantization tool from onnx to onnxruntime

* Fix some issues

* Use u8_s8 for asymmetric mode and u8_u8 for symmetric mode irrespective of whether inputs are initializers or from previous

* Address PR comments

* Fix error message formatting

* Separate static/dynamic and quantization mode