[Feature Request] socks5h proxy support

[hawktang]

could we add support for socks5h proxy support like curl. like

curl -x socks5h://proxy.example.com http://www.example.com/ curl --socks5-hostname proxy.example.com http://www.example.com/

which can also explicit assign http(s) proxy if possible honor env like all_proxy, ALL_PRXOY