fix compilation problems

Implement concat op for FPGA track close #935

Modify FPGA kernels to comply to Gtype close #932

Fix bugs to format data for FPGA track close #930

repair bug of dropout op

add split/bilinear_interp/flatten/op for support fssd #924

to be impl.  for fssd
add googlenetv1 and fssd unit test

add border check in gemm

add openmp support for ios

repair bugs in op kernels for FPGA track close #914

add nlp net supported &&add unittest &&add singlenet build #911

Update to format data for FPGA track close #908

fix #906 compile on ios

Add test code for FPGA track close #904