golang pkg simple bind for opencv4

package uses cgo to compile the stdccv static library and link

set system env(or use golang build params)

CGO_CPPFLAGS=-I{stdccv include dir};
CGO_LDFLAGS=-LD{stdccv dynamic lib dir} -l{stdccv lib name}

use CMakeLists.txt (project root dir) compile dynamic lib,go build add

Some modules of opencv are included by default,can be ignored using the build tag

example:ignore opencv_highgui go build -tags=no_cv_highgui

Supported tags and corresponding opencv modules

1. set CGO_CPPFLAGS and CGO_LDFLAGS link opencv include and lib dir
2. add build tags custom_cv for go build

install opencv

brew install opencv

install pkgconfig

brew install pkgconfig