A stunnel-like util write by golang

• listen plain, forward through plain
• listen plain, forward through TLS
• listen TLS, forward through plain
• listen TLS, forward through TLS

go get github.com/fangdingjun/gtunnel
cp $GOPATH/src/github.com/fangdingjun/config_example.yaml config.yaml
vim config.yaml
$GOPATH/bin/gtunnel -c config.yaml