Created by: grygielski

Final version target: Release 1.7 Current state: First functional version has been made. Its performance was tested on AVX2 and AVX512 machines (containing 6248 machine) and compared to current develop branch. Performance of FP32 is mostly the same but Int8 has improved a little (~5%). Significant changes: This version does not contain any significant changes touching PaddlePaddle core. There are mostly cosmetic and MKL-DNN core changes. Future plans: We will maintain and resolve conflicts if needed. Refactoring of some mkldnn ops are also in future plans.

This PR exceeds files and code lines limit but we cannot divide it because whole mkl-dnn infrastructure has been rebuilt.