change default socket file dir to /var/run/god or ~/.god/sockets. custom setting via class attribute available as well.
new tests and updates for socket file changes
Use GOD_PORT environment variable

Support for multiple instances is helpful but it is hampered by the need to specify the -p option all the time. This change allows you to override the default port in your environment. Setting this to 0 means that your instance will never clash with other users.