* Support port forwarding of literal IPv6 addresses
To disambiguate between colons as host:port separators and as IPv6 address separators, literal IPv6 addresses use square brackets around the address (https://en.wikipedia.org/wiki/IPv6_address#Literal_IPv6_addresses_in_network_resource_identifiers). So host ::1, port 22 is written as [::1]:22, and therefore a simple concatenation of host, colon, and port doesn't work. Fortunately net.JoinHostPort already implements this functionality, so with a bit of type gymnastics we can generate dest in an IPv6-safe way.
* Support port forwarding of literal IPv6 addresses
To disambiguate between colons as host:port separators and as IPv6 address separators, literal IPv6 addresses use square brackets around the address (https://en.wikipedia.org/wiki/IPv6_address#Literal_IPv6_addresses_in_network_resource_identifiers). So host ::1, port 22 is written as [::1]:22, and therefore a simple concatenation of host, colon, and port doesn't work. Fortunately net.JoinHostPort already implements this functionality, so with a bit of type gymnastics we can generate dest in an IPv6-safe way.
