Add/Refine unit tests

optimize norm_op

fix a bug in FPGA track

add norm_op

update fp32 and fp16 inter-transformation function in FPGA tracker fixed #1378

Implement sequence_expand, sequence_pool, sequence_softmax and tanh op for CPU

Optimize int8/float 5x5 depthwise conv and 2x2 pooling, add aarch64 macros to make compilation no problem

Avoid memory leakage for FPGA track, close #1372

add dwconv compute function in FPGA and update some other files fixed#1368