SOCKS5 proxy authentication didn't work with the system properties
java.net.socks.username and java.net.socks.password. Instead we now
use the Authenticator class to provide a proxy authenticator.
This step should enable the application to handle different camsites.
At the moment only chaturbate is available, but others like MFC can
now be added. There might be still some things to do, like the settings
and HttpClient etc. But this is the first step to support more sites
than only Chatubate.