Based-on-code-by: Brian Long <briandlong@gmail.com>

Allow FAH client preconfiguration from command-line.

Following options are now available:
--fah-username
--fah-team
--fah-passkey
--fah-proxy-host
--fah-proxy-port

Note that fahinstall doesn't currently perform any input
validation and values are stored in client.cfg verbatim.