fix:#785

add quantilization func to fusion_fc and fc_relu kernel closed #783

change FPGA kernel pointer type close #781

addeded fpga softmax kernel:#779

Correct feed_op for FPGA track close #777

add simple build for mobilenetssd  close #773

update README

Recover test-googlenet.cpp close #770

Need to realize conv_bn & conv_bn_relu for FPGA googlenet close #768

update performance data in README

optimize multithreading 3x3 s2 depthwise_conv