Created by: sfraczek

in files graph_pattern_detector.cc, graph_pattern_detector.h, cpu_quantize_pass.cc, cpu_quantize_pass.h, mkldnn_quantizer.cc, mkldnn_quantizer.cc:

• added Concat quantization code

in file mkldnn_quantizer.cc:

• handling of multiple tensors wired to single input
• extended list of ops that do not modify the sign of values in tensor,
• added setting type to unsigned after regular ReLU op