Created by: qili93

1. add 2 new X86 kernels of box_coder and density_prior_box and pass unit test case
2. fix X86 build error on MAC of "lite/api/cxx_api_impl.cc"
3. remove bind kernel of lite_quant_dequant_fuse_pass in "quant_dequant_fuse_pass.cc" (与晓伟如流确认过)