Allow erizo connections to hostnames and via SSL.

In order to get around CORS requirements, it's helpful to be able to
connect by a DNS name instead of an IP address. Allow the hostname
provided in tokens to be configurable. Also allow setups where something
like nginx fronts erizo_controller and provides SSL termination.
Always include the port in the hostname.

This will take care of the case where the page serving erizo is on a
strange port. In that case, socket.io attempts to connect on the port of
window.location if the port is not specified.
Merge pull request #101 from byronclark/configurable-erizo-host-settings

Allow erizo connections to hostnames and via SSL.