Add support for hostname instead of ip address in Controller.from_port

[Dekwin]

Add support for hostname(like "tor-container", or "localhost") as address parameter in Controller.from_port
Currently address parameter only supports ipv4 address.

It is useful when Tor is running in one Docker container, but the Stem connection establishing from another container.

example:

from stem.control import Controller

address="127.0.0.1"
# address="localhost" add support for this, currently this throws an exception
with Controller.from_port(address=address, port=9051) as controller:
   ...

[atagar]

Oddly GitHub didn't provide a useful link for the PR. Here it is: #122