* Disable incorrect check for hidden services in Socket
Hidden services can only be accessed with an HTTP proxy, in which
case the host seen by the Socket class will be the proxy, not the
target host.
Hidden services are already filtered in `Request#initialize`.
* Use our Socket class to connect to HTTP proxies
Avoid the timeout logic being bypassed
* Add support for IP addresses in Request::Socket
* Refactor a bit, no need to keep the DNS resolver around
ac1fec5be3